drm/msm/atomic: Don't leak atomic commit object when commit fails

If the atomic commit fails due to completion wait interruption the
atomic commit object is not freed and is thus leaked. Free it.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/msm_atomic.c

@@ -219,8 +219,10 @@ int msm_atomic_commit(struct drm_device *dev,
 	 * mark our set of crtc's as busy:
 	 */
 	ret = start_atomic(dev->dev_private, c->crtc_mask);
-	if (ret)
+	if (ret) {
+		kfree(c);
 		return ret;
+	}
 
 	/*
 	 * This is the point of no return - everything below never fails except