smb: server: Fix building with GCC 15

GCC 15 introduces -Werror=unterminated-string-initialization by default,
this results in the following build error

fs/smb/server/smb_common.c:21:35: error: initializer-string for array of 'char' is too long [-Werror=unterminated-string-ini
tialization]
   21 | static const char basechars[43] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%";
      |                                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

To this we are replacing char basechars[43] with a character pointer
and then using strlen to get the length.

Signed-off-by: Brahmajit Das <[email protected]>
Signed-off-by: Namjae Jeon <[email protected]>

smb_common.c

@@ -19,8 +19,8 @@
 #include "mgmt/share_config.h"
 
 /*for shortname implementation */
-static const char basechars[43] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%";
-#define MANGLE_BASE (sizeof(basechars) / sizeof(char) - 1)
+static const char *basechars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%";
+#define MANGLE_BASE (strlen(basechars) - 1)
 #define MAGIC_CHAR '~'
 #define PERIOD '.'
 #define mangle(V) ((char)(basechars[(V) % MANGLE_BASE]))