drm/qxl: handle shadow in primary destroy

qxl_primary_atomic_disable must check whenever the framebuffer bo has a
shadow surface and in case it has check the shadow primary status.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20210204145712.1531203-8-kraxel@redhat.com

drivers/gpu/drm/qxl/qxl_display.c

@@ -562,6 +562,8 @@ static void qxl_primary_atomic_disable(struct drm_plane *plane,
 	if (old_state->fb) {
 		struct qxl_bo *bo = gem_to_qxl_bo(old_state->fb->obj[0]);
 
+		if (bo->shadow)
+			bo = bo->shadow;
 		if (bo->is_primary) {
 			qxl_io_destroy_primary(qdev);
 			bo->is_primary = false;