fortify: Cleanup temp file also on non-successful exit

fortify: Cleanup temp file also on non-successful exit

Ensure cleanup of test_fortify.sh's temporary file also on script
interruption, or some common signals.

Reported-by: WangYuli <wangyuli@aosc.io>
Closes: https://lore.kernel.org/linux-kbuild/20251112114725.287349-1-wangyuli@aosc.io/
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: WangYuli <wangyuli@aosc.io>
Signed-off-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20260114-fortify-improve-handling-of-tempfile-v2-2-63b86c4dbd0e@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>