net: phy: mdio: 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 <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/phy/mdio-mux-mmioreg.c

···
 		if (!iprop || len != sizeof(uint32_t)) {
 			dev_err(&pdev->dev, "mdio-mux child node %s is "
 				"missing a 'reg' property\n", np2->full_name);
+			of_node_put(np2);
 			return -ENODEV;
 		}
 		if (be32_to_cpup(iprop) & ~s->mask) {
 			dev_err(&pdev->dev, "mdio-mux child node %s has "
 				"a 'reg' value with unmasked bits\n",
 				np2->full_name);
+			of_node_put(np2);
 			return -ENODEV;
 		}
 	}