net: smsc: fix return type of ndo_start_xmit function

The method ndo_start_xmit() is defined as returning an 'netdev_tx_t',
which is a typedef for an enum type, so make sure the implementation in
this driver has returns 'netdev_tx_t' value, and change the function
return type to netdev_tx_t.

Found by coccinelle.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/smsc/smc911x.c

@@ -513,7 +513,8 @@ static void smc911x_hardware_send_pkt(struct net_device *dev)
  * now, or set the card to generates an interrupt when ready
  * for the packet.
  */
-static int smc911x_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
+static netdev_tx_t
+smc911x_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct smc911x_local *lp = netdev_priv(dev);
 	unsigned int free;

drivers/net/ethernet/smsc/smc91x.c

@@ -638,7 +638,8 @@ done:	if (!THROTTLE_TX_PKTS)
  * now, or set the card to generates an interrupt when ready
  * for the packet.
  */
-static int smc_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
+static netdev_tx_t
+smc_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct smc_local *lp = netdev_priv(dev);
 	void __iomem *ioaddr = lp->base;

drivers/net/ethernet/smsc/smsc911x.c

@@ -1786,7 +1786,8 @@ static int smsc911x_stop(struct net_device *dev)
 }
 
 /* Entry point for transmitting a packet */
-static int smsc911x_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
+static netdev_tx_t
+smsc911x_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct smsc911x_data *pdata = netdev_priv(dev);
 	unsigned int freespace;