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>
diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
index 871aa21..18fd643 100644
--- a/drivers/gpu/drm/msm/msm_atomic.c
+++ b/drivers/gpu/drm/msm/msm_atomic.c
@@ -219,8 +219,10 @@
 	 * 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