net: stmmac: remove unnecessary pci_set_drvdata()

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c

@@ -138,7 +138,6 @@ static void stmmac_pci_remove(struct pci_dev *pdev)
 
 	stmmac_dvr_remove(ndev);
 
-	pci_set_drvdata(pdev, NULL);
 	pci_iounmap(pdev, priv->ioaddr);
 	pci_release_regions(pdev);
 	pci_disable_device(pdev);