CR-1214907 Modified strcture data element from fixed size to flexible array.

[ManojTakasi]

Problem solved by the commit

https://jira.xilinx.com/browse/CR-1214907 We are getting UBSAN: array-index-out-of-bounds call trace while compiling xocl xclmgmt drivers in ubuntu 24.04

Bug / issue (if any) fixed, which PR introduced the bug, how it was discovered

Reference: https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays

How problem was solved, alternative solutions (if any) and why they were rejected

Added macros to pick flexible arrays when comipiling kernel code.

Risks (if any) associated the changes in the commit

Modifications are in common files and will affect all platforms.

What has been tested and how, request additional testing if necessary

Tested on u250 by running xrt-smi examine. Ran vadd and graph testcases on vck190 .

Documentation impact (if any)

NA

[stsoe]

The changes to ert.h are exactly what flexible arrays should be all over the place. Iit's so confusing to have data[1], but unfortunately much code in user space accounts for the one default element; so the guard to enable for kernel space only is good.