USB: ehci-platform: 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-platform.c

@@ -146,7 +146,6 @@ static int ehci_platform_remove(struct platform_device *dev)
 
 	usb_remove_hcd(hcd);
 	usb_put_hcd(hcd);
-	platform_set_drvdata(dev, NULL);
 
 	if (pdata->power_off)
 		pdata->power_off(dev);