usb: cdns3: Fix Wunused-but-set-variable warning

drivers/usb/cdns3/ep0.c: In function cdns3_ep0_feature_handle_device:
drivers/usb/cdns3/ep0.c:290:6: warning: variable wIndex set but not used [-Wunused-but-set-variable]
drivers/usb/cdns3/ep0.c:289:6: warning: variable wValue set but not used [-Wunused-but-set-variable]

wIndex is never used, so remove it.
wValue should be use in the switch statement.

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 7733f6c32e ("usb: cdns3: Add Cadence USB3 DRD Driver")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20190903120615.19504-1-yuehaibing@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/cdns3/ep0.c

@@ -287,15 +287,13 @@ static int cdns3_ep0_feature_handle_device(struct cdns3_device *priv_dev,
 	enum usb_device_speed speed;
 	int ret = 0;
 	u32 wValue;
-	u32 wIndex;
 	u16 tmode;
 
 	wValue = le16_to_cpu(ctrl->wValue);
-	wIndex = le16_to_cpu(ctrl->wIndex);
 	state = priv_dev->gadget.state;
 	speed = priv_dev->gadget.speed;
 
-	switch (ctrl->wValue) {
+	switch (wValue) {
 	case USB_DEVICE_REMOTE_WAKEUP:
 		priv_dev->wake_up_flag = !!set;
 		break;