convert hamradio drivers to netdev_txreturnt_t

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c
index ac191ef..33b55f7 100644
--- a/drivers/net/hamradio/mkiss.c
+++ b/drivers/net/hamradio/mkiss.c
@@ -525,7 +525,7 @@
 }
 
 /* Encapsulate an AX.25 packet and kick it into a TTY queue. */
-static int ax_xmit(struct sk_buff *skb, struct net_device *dev)
+static netdev_tx_t ax_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct mkiss *ax = netdev_priv(dev);