usbnet: don't initialize transfer buffer before submit status URB

The line below in intr_complete isn't needed,

	memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);

so just remove it.
Signed-off-by: NMing Lei <tom.leiming@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/usb/usbnet.c

@@ -209,7 +209,6 @@ static void intr_complete (struct urb *urb)
 	if (!netif_running (dev->net))
 		return;
 
-	memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
 	status = usb_submit_urb (urb, GFP_ATOMIC);
 	if (status != 0)
 		netif_err(dev, timer, dev->net,