mips: ralink: fix a refcount leak in ill_acc_of_setup()

of_node_put(np) needs to be called when pdev == NULL.
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/ralink/ill_acc.c

@@ -61,6 +61,7 @@ static int __init ill_acc_of_setup(void)
 	pdev = of_find_device_by_node(np);
 	if (!pdev) {
 		pr_err("%pOFn: failed to lookup pdev\n", np);
+		of_node_put(np);
 		return -EINVAL;
 	}