pinctrl: at91-pio4: add missing of_node_put

The device node iterators perform an of_node_get on each iteration, so a
jump out of the loop requires an of_node_put.

The semantic patch that fixes this problem is as follows
(http://coccinelle.lip6.fr):

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

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

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-at91-pio4.c

@@ -576,8 +576,10 @@ static int atmel_pctl_dt_node_to_map(struct pinctrl_dev *pctldev,
 		for_each_child_of_node(np_config, np) {
 			ret = atmel_pctl_dt_subnode_to_map(pctldev, np, map,
 						    &reserved_maps, num_maps);
-			if (ret < 0)
+			if (ret < 0) {
+				of_node_put(np);
 				break;
+			}
 		}
 	}