static void mcs_receive_irq(struct urb *urb);
static void mcs_send_irq(struct urb *urb);
-static int mcs_hard_xmit(struct sk_buff *skb, struct net_device *netdev);
+static netdev_tx_t mcs_hard_xmit(struct sk_buff *skb,
+ struct net_device *netdev);
static int mcs_probe(struct usb_interface *intf,
const struct usb_device_id *id);