r8169: remove remaining call to mdiobus_unregister

After having switched to devm_mdiobus_register() also this remaining
call to mdiobus_unregister() can be removed.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169_main.c

@@ -4990,7 +4990,6 @@ static void rtl_remove_one(struct pci_dev *pdev)
 	netif_napi_del(&tp->napi);
 
 	unregister_netdev(dev);
-	mdiobus_unregister(tp->phydev->mdio.bus);
 
 	rtl_release_firmware(tp);