pinctrl: at91: 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>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-at91.c

@@ -1122,8 +1122,10 @@ static int at91_pinctrl_parse_functions(struct device_node *np,
 		func->groups[i] = child->name;
 		grp = &info->groups[grp_index++];
 		ret = at91_pinctrl_parse_groups(child, grp, info, i++);
-		if (ret)
+		if (ret) {
+			of_node_put(child);
 			return ret;
+		}
 	}
 
 	return 0;
@@ -1196,6 +1198,7 @@ static int at91_pinctrl_probe_dt(struct platform_device *pdev,
 		ret = at91_pinctrl_parse_functions(child, info, i++);
 		if (ret) {
 			dev_err(&pdev->dev, "failed to parse function\n");
+			of_node_put(child);
 			return ret;
 		}
 	}