selftests: core: include linux/close_range.h for CLOSE_RANGE_* macros

Correct header file is needed for getting CLOSE_RANGE_* macros. 
Previously it was tested with newer glibc which didn't show the need to
include the header which was a mistake.

Link: https://lkml.kernel.org/r/20231024155137.219700-1-usama.anjum@collabora.com


Fixes: ec544249 ("selftests: core: remove duplicate defines")
Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com>
Link: https://lore.kernel.org/all/7161219e-0223-d699-d6f3-81abd9abf13b@arm.com


Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>