igt: fb: Clear YUV dumb buffers

YUV dumb buffers, just like i915 GEM buffers also need to be cleared once
allocated. Make sure it happens.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
diff --git a/lib/igt_fb.c b/lib/igt_fb.c
index dea390b..6fe0d08 100644
--- a/lib/igt_fb.c
+++ b/lib/igt_fb.c
@@ -596,6 +596,9 @@
 	fb->gem_handle = kmstest_dumb_create(fd, fb->width, fb->height,
 					     bpp, strides, &fb->size);
 
+	if (igt_format_is_yuv(fb->drm_format))
+		clear_yuv_buffer(fb);
+
 	return fb->gem_handle;
 }