net: moxa: Fix use correct return type for ndo_start_xmit()

The method ndo_start_xmit() returns a value of type netdev_tx_t. Fix
the ndo function to use the correct type.
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/moxa/moxart_ether.c

@@ -331,14 +331,15 @@ static irqreturn_t moxart_mac_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static int moxart_mac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+static netdev_tx_t moxart_mac_start_xmit(struct sk_buff *skb,
+					 struct net_device *ndev)
 {
 	struct moxart_mac_priv_t *priv = netdev_priv(ndev);
 	void *desc;
 	unsigned int len;
 	unsigned int tx_head;
 	u32 txdes1;
-	int ret = NETDEV_TX_BUSY;
+	netdev_tx_t ret = NETDEV_TX_BUSY;
 
 	spin_lock_irq(&priv->txlock);