net: fec_mpc52xx_phy: 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: Libo Chen <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/freescale/fec_mpc52xx_phy.c

···
 	struct mpc52xx_fec_mdio_priv *priv = bus->priv;
 
 	mdiobus_unregister(bus);
-	dev_set_drvdata(dev, NULL);
 	iounmap(priv->regs);
 	kfree(priv);
 	mdiobus_free(bus);