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>
diff --git a/drivers/net/tlan.c b/drivers/net/tlan.c
index 70c9ec4..49e273b 100644
--- a/drivers/net/tlan.c
+++ b/drivers/net/tlan.c
@@ -289,7 +289,7 @@
 static void	TLan_Eisa_Cleanup( void );
 static int      TLan_Init( struct net_device * );
 static int	TLan_Open( struct net_device *dev );
-static int	TLan_StartTx( struct sk_buff *, struct net_device *);
+static netdev_tx_t TLan_StartTx( struct sk_buff *, struct net_device *);
 static irqreturn_t TLan_HandleInterrupt( int, void *);
 static int	TLan_Close( struct net_device *);
 static struct	net_device_stats *TLan_GetStats( struct net_device *);
@@ -1083,7 +1083,7 @@
 	 *
 	 **************************************************************/
 
-static int TLan_StartTx( struct sk_buff *skb, struct net_device *dev )
+static netdev_tx_t TLan_StartTx( struct sk_buff *skb, struct net_device *dev )
 {
 	TLanPrivateInfo *priv = netdev_priv(dev);
 	dma_addr_t	tail_list_phys;