drm/nouveau: unreference fence after syncing

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c b/drivers/gpu/drm/nouveau/nouveau_display.c
index acec774..29c3efd 100644
--- a/drivers/gpu/drm/nouveau/nouveau_display.c
+++ b/drivers/gpu/drm/nouveau/nouveau_display.c
@@ -608,6 +608,7 @@
 	fence = nouveau_fence_ref(new_bo->bo.sync_obj);
 	spin_unlock(&new_bo->bo.bdev->fence_lock);
 	ret = nouveau_fence_sync(fence, chan);
+	nouveau_fence_unref(&fence);
 	if (ret)
 		return ret;