net: wan: remove unnecessary platform_set_drvdata()

The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d0631001288a5974afc0b2a5f568bcdecb4d
(device-core: Ensure drvdata = NULL when no driver is bound).
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: David S. Miller <davem@davemloft.net>

drivers/net/wan/ixp4xx_hss.c

@@ -1384,7 +1384,6 @@ static int hss_remove_one(struct platform_device *pdev)
 	unregister_hdlc_device(port->netdev);
 	free_netdev(port->netdev);
 	npe_release(port->npe);
-	platform_set_drvdata(pdev, NULL);
 	kfree(port);
 	return 0;
 }