usbnet: ipheth: fix ipheth_tx()'s return type

The method ndo_start_xmit() is defined as returning an 'netdev_tx_t',
which is a typedef for an enum type, but the implementation in this
driver returns an 'int'.

Fix this by returning 'netdev_tx_t' in this driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/ipheth.c

@@ -358,7 +358,7 @@ static int ipheth_close(struct net_device *net)
 	return 0;
 }
 
-static int ipheth_tx(struct sk_buff *skb, struct net_device *net)
+static netdev_tx_t ipheth_tx(struct sk_buff *skb, struct net_device *net)
 {
 	struct ipheth_device *dev = netdev_priv(net);
 	struct usb_device *udev = dev->udev;