usbnet: Remove private stats structure

Now that nothing uses the private stats structure we can remove it.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/usb/usbnet.h

@@ -42,7 +42,6 @@ struct usbnet {
 
 	/* protocol/interface state */
 	struct net_device	*net;
-	struct net_device_stats	stats;
 	int			msg_enable;
 	unsigned long		data [5];
 	u32			xid;