test/gem_gtt_hog: bail out earlier

This way we properly skip instead of failing hard. Just result
polish when running on non-intel systems.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/tests/gem_gtt_hog.c b/tests/gem_gtt_hog.c
index 53d7dd7..5f14109 100644
--- a/tests/gem_gtt_hog.c
+++ b/tests/gem_gtt_hog.c
@@ -150,6 +150,10 @@
 	pid_t children[64];
 	int n;
 
+	/* check for an intel gpu before goint nuts. */
+	int fd = drm_open_any();
+	close(fd);
+
 	igt_skip_on_simulation();
 
 	gettimeofday(&start, NULL);