net: ethernet: bgmac: Fix refcount leak in bcma_mdio_mii_register

of_get_child_by_name() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
Add missing of_node_put() to avoid refcount leak.

Fixes: 55954f3b ("net: ethernet: bgmac: move BCMA MDIO Phy code into a separate file")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220603133238.44114-1-linmq006@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bgmac-bcma-mdio.c

@@ -234,6 +234,7 @@ struct mii_bus *bcma_mdio_mii_register(struct bgmac *bgmac)
 	np = of_get_child_by_name(core->dev.of_node, "mdio");
 
 	err = of_mdiobus_register(mii_bus, np);
+	of_node_put(np);
 	if (err) {
 		dev_err(&core->dev, "Registration of mii bus failed\n");
 		goto err_free_bus;