drm/qxl: qxl_release leak in qxl_draw_dirty_fb()

ret should be changed to release allocated struct qxl_release

Cc: stable@vger.kernel.org
Fixes: 8002db63 ("qxl: convert qxl driver to proper use for reservations")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Link: http://patchwork.freedesktop.org/patch/msgid/22cfd55f-07c8-95d0-a2f7-191b7153c3d4@virtuozzo.comSigned-off-by: Gerd Hoffmann <kraxel@redhat.com>

drivers/gpu/drm/qxl/qxl_draw.c

@@ -209,9 +209,10 @@ void qxl_draw_dirty_fb(struct qxl_device *qdev,
 		goto out_release_backoff;
 
 	rects = drawable_set_clipping(qdev, num_clips, clips_bo);
-	if (!rects)
+	if (!rects) {
+		ret = -EINVAL;
 		goto out_release_backoff;
-
+	}
 	drawable = (struct qxl_drawable *)qxl_release_map(qdev, release);
 
 	drawable->clip.type = SPICE_CLIP_TYPE_RECTS;