[media] v4l: xilinx-vipp: add missing of_node_put

for_each_child_of_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
expression root,e;
local idexpression child;
@@

 for_each_child_of_node(root, child) {
   ... when != of_node_put(child)
       when != e = child
(
   return child;
|
+  of_node_put(child);
?  return ...;
)
   ...
 }
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/platform/xilinx/xilinx-vipp.c

@@ -476,8 +476,10 @@ static int xvip_graph_dma_init(struct xvip_composite_device *xdev)
 
 	for_each_child_of_node(ports, port) {
 		ret = xvip_graph_dma_init_one(xdev, port);
-		if (ret < 0)
+		if (ret < 0) {
+			of_node_put(port);
 			return ret;
+		}
 	}
 
 	return 0;