wireless: rtl818x: 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: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rtl818x/rtl8180/dev.c

@@ -1122,7 +1122,6 @@ static int rtl8180_probe(struct pci_dev *pdev,
 	iounmap(priv->map);
 
  err_free_dev:
-	pci_set_drvdata(pdev, NULL);
 	ieee80211_free_hw(dev);
 
  err_free_reg: