net: can: at91_can: remove unnecessary platform_set_drvdata()

The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d063
(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: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/at91_can.c

@@ -1393,8 +1393,6 @@ static int at91_can_remove(struct platform_device *pdev)
 
 	unregister_netdev(dev);
 
-	platform_set_drvdata(pdev, NULL);
-
 	iounmap(priv->reg_base);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);