net: mv643xx_eth: add missing of_node_put

for_each_available_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_available_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>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mv643xx_eth.c

@@ -2817,8 +2817,10 @@ static int mv643xx_eth_shared_of_probe(struct platform_device *pdev)
 
 	for_each_available_child_of_node(np, pnp) {
 		ret = mv643xx_eth_shared_of_add_port(pdev, pnp);
-		if (ret)
+		if (ret) {
+			of_node_put(pnp);
 			return ret;
+		}
 	}
 	return 0;
 }