tests/testdisplay: Fix test status check fumble

This is a regression from

4306538d1d3f60877866c39c9ca953cc5e541dae is the first bad commit
commit 4306538d1d3f60877866c39c9ca953cc5e541dae
Author:     Daniel Vetter <daniel.vetter@ffwll.ch>
AuthorDate: Thu Oct 2 11:18:20 2014 +0200
Commit:     Daniel Vetter <daniel.vetter@ffwll.ch>
CommitDate: Thu Oct 2 11:34:55 2014 +0200

    tests: Sprinkle missing igt_exit() where needed.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=85582
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/testdisplay.c b/tests/testdisplay.c
index 04e41db8..09e07f0f 100644
--- a/tests/testdisplay.c
+++ b/tests/testdisplay.c
@@ -786,7 +786,7 @@ out_mainloop:
 out_close:
 	close(drm_fd);
 
-	igt_assert(ret);
+	igt_assert(ret == 0);
 
 	igt_exit();
 }