drm: Clean up planes in atomic commit helper failure path

If waiting for fences fails for blocking commits, planes must be cleaned
up before returning.

Cc: stable@vger.kernel.org
Fixes: f6ce410a ("drm/fence: allow fence waiting to be interrupted by userspace")
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170102231427.7192-1-laurent.pinchart@ideasonboard.com

drivers/gpu/drm/drm_atomic_helper.c

@@ -1259,9 +1259,11 @@ int drm_atomic_helper_commit(struct drm_device *dev,
 
 	if (!nonblock) {
 		ret = drm_atomic_helper_wait_for_fences(dev, state, true);
-		if (ret)
+		if (ret) {
+			drm_atomic_helper_cleanup_planes(dev, state);
 			return ret;
 		}
+	}
 
 	/*
 	 * This is the point of no return - everything below never fails except