net: fsl_pq_mdio: remove unnecessary dev_set_drvdata()

Unnecessary dev_set_drvdata() is removed, because the driver core
clears the driver data to NULL after device_release or on probe failure.
Signed-off-by: NLibo Chen <libo.chen@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/fsl_pq_mdio.c

@@ -468,8 +468,6 @@ static int fsl_pq_mdio_remove(struct platform_device *pdev)
 
 	mdiobus_unregister(bus);
 
-	dev_set_drvdata(device, NULL);
-
 	iounmap(priv->map);
 	mdiobus_free(bus);