mdio: mux: fix device_node_continue.cocci warnings

Device node iterators put the previous value of the index variable, so an
explicit put causes a double put.

In particular, of_mdiobus_register can fail before doing anything
interesting, so one could view it as a no-op from the reference count
point of view.

Generated by: scripts/coccinelle/iterators/device_node_continue.cocci

CC: Jon Mason <jon.mason@broadcom.com>
Signed-off-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/mdio-mux.c

@@ -169,7 +169,6 @@ int mdio_mux_init(struct device *dev,
 		if (r) {
 			mdiobus_free(cb->mii_bus);
 			devm_kfree(dev, cb);
-			of_node_put(child_bus_node);
 		} else {
 			cb->next = pb->children;
 			pb->children = cb;