net: emaclite: Fix MDIO bus unregister bug

Since 'has_mdio' flag is not used,sequence insmod->rmmod-> insmod
leads to failure as MDIO unregister doesn't happen in .remove().
Fix it by checking MII bus pointer instead.

Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/xilinx/xilinx_emaclite.c

@@ -1191,7 +1191,7 @@ static int xemaclite_of_remove(struct platform_device *of_dev)
 	struct net_local *lp = netdev_priv(ndev);
 
 	/* Un-register the mii_bus, if configured */
-	if (lp->has_mdio) {
+	if (lp->mii_bus) {
 		mdiobus_unregister(lp->mii_bus);
 		mdiobus_free(lp->mii_bus);
 		lp->mii_bus = NULL;