kms_3d: Close device before exit

Close the device fd before we check for leaks during the atexit
handlers.

Signed-off-by: Chris Wilson <chris.p.wilson@intel.com>
Reviewed-by: Kamil Konieczny <kamil.konieczny@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

tests/kms_3d.c

@@ -111,4 +111,5 @@ igt_simple_main
 	kmstest_force_edid(drm_fd, connector, NULL);
 
 	drmModeFreeConnector(connector);
+	close(drm_fd);
 }