net: arc_emac: fix arc_emac_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: NLuc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/arc/emac_main.c

@@ -673,7 +673,7 @@ static struct net_device_stats *arc_emac_stats(struct net_device *ndev)
  *
  * This function is invoked from upper layers to initiate transmission.
  */
-static int arc_emac_tx(struct sk_buff *skb, struct net_device *ndev)
+static netdev_tx_t arc_emac_tx(struct sk_buff *skb, struct net_device *ndev)
 {
 	struct arc_emac_priv *priv = netdev_priv(ndev);
 	unsigned int len, *txbd_curr = &priv->txbd_curr;