netdev: convert bulk of drivers to netdev_tx_t

In a couple of cases collapse some extra code like:
   int retval = NETDEV_TX_OK;
   ...
   return retval;
into
   return NETDEV_TX_OK;

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/chelsio/sge.c

@@ -1776,7 +1776,7 @@ static inline int eth_hdr_len(const void *data)
 /*
  * Adds the CPL header to the sk_buff and passes it to t1_sge_tx.
  */
-int t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
+netdev_tx_t t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct adapter *adapter = dev->ml_priv;
 	struct sge *sge = adapter->sge;

drivers/net/chelsio/sge.h

@@ -78,7 +78,7 @@ void t1_sge_destroy(struct sge *);
 irqreturn_t t1_interrupt(int irq, void *cookie);
 int t1_poll(struct napi_struct *, int);
 
-int t1_start_xmit(struct sk_buff *skb, struct net_device *dev);
+netdev_tx_t t1_start_xmit(struct sk_buff *skb, struct net_device *dev);
 void t1_set_vlan_accel(struct adapter *adapter, int on_off);
 void t1_sge_start(struct sge *);
 void t1_sge_stop(struct sge *);