lib: exit immediately if igt_fail is called in an exit handler

Exit immediately if the test is already exiting and igt_fail is called.
This can happen if an igt_assert fails in an exit handler.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91349
Signed-off-by: Thomas Wood <thomas.wood@intel.com>
1 file changed