Memory leak when failing to acquire a camera

[kbingham]

Trivial, and not likely to be permantantly losing memory - but my build tests report a memory leak using LeakSanitizer if I try to run simple-cam while the (first/only?) camera is in use elsewhere:

==3944173==ERROR: LeakSanitizer: detected memory leaks
Indirect leak of 64 byte(s) in 1 object(s) allocated from:
    #0 0x7f5fa39bf1c7 in operator new(unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cpp:99
    #1 0x7f5f9fe7711e in __gnu_cxx::new_allocator<std::_Rb_tree_node<std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > > > >::allocate(unsigned long, void const*) (/home/kbingham/iob/libcamera/ci/integrator/builds/unit-tests/src/libcamera/libcamera.so.0+0x284f11e)
    #2 0x7f5f9fe7674f in std::allocator_traits<std::allocator<std::_Rb_tree_node<std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > > > > >::allocate(std::allocator<std::_Rb_tree_node<std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > > > >&, unsigned long) (/home/kbingham/iob/libcamera/ci/integrator/builds/unit-tests/src/libcamera/libcamera.so.0+0x284e74f)
    #3 0x7f5f9fe74cd7 in std::_Rb_tree<libcamera::Stream*, std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > >, std::_Select1st<std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > > >, std::less<libcamera::Stream*>, std::allocator<std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > > > >::_M_get_node() (/home/kbingham/iob/libcamera/ci/integrator/builds/unit-tests/src/libcamera/libcamera.so.0+0x284ccd7)
    #4 0x7f5f9fe7147c in std::_Rb_tree_node<std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > > >* std::_Rb_tree<libcamera::Stream*, std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > >, std::_Select1st<std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > > >, std::less<libcamera::Stream*>, std::allocator<std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > > > >::_M_create_node<std::piecewise_construct_t const&, std::tuple<libcamera::Stream* const&>, std::tuple<> >(std::piecewise_construct_t const&, std::tuple<libcamera::Stream* const&>&&, std::tuple<>&&) /usr/include/c++/11/bits/stl_tree.h:611
    #5 0x7f5f9fe6edf2 in std::_Rb_tree_iterator<std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > > > std::_Rb_tree<libcamera::Stream*, std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > >, std::_Select1st<std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > > >, std::less<libcamera::Stream*>, std::allocator<std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > > > >::_M_emplace_hint_unique<std::piecewise_construct_t const&, std::tuple<libcamera::Stream* const&>, std::tuple<> >(std::_Rb_tree_const_iterator<std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > > >, std::piecewise_construct_t const&, std::tuple<libcamera::Stream* const&>&&, std::tuple<>&&) /usr/include/c++/11/bits/stl_tree.h:2431
    #6 0x7f5f9fe6c46e in std::map<libcamera::Stream*, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > >, std::less<libcamera::Stream*>, std::allocator<std::pair<libcamera::Stream* const, std::vector<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> >, std::allocator<std::unique_ptr<libcamera::FrameBuffer, std::default_delete<libcamera::FrameBuffer> > > > > > >::operator[](libcamera::Stream* const&) /usr/include/c++/11/bits/stl_map.h:501
    #7 0x7f5f9fe69b3d in libcamera::FrameBufferAllocator::allocate(libcamera::Stream*) ../../src/libcamera/src/libcamera/framebuffer_allocator.cpp:96
    #8 0x55f47f3e74b4 in main ../../src/simple-cam/simple-cam.cpp:341
    #9 0x7f5f9c563d8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58

Indirect leak of 64 byte(s) in 1 object(s) allocated from:
    #0 0x7f5fa39bf1c7 in operator new(unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cpp:99
    #1 0x55f47f3e70da in main ../../src/simple-cam/simple-cam.cpp:338
    #2 0x7f5f9c563d8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58

SUMMARY: AddressSanitizer: 128 byte(s) leaked in 2 allocation(s).
/home/kbingham/iob/libcamera/ci/integrator