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/smc9194.c b/drivers/net/smc9194.c
index 0a1b6f4..934a120 100644
--- a/drivers/net/smc9194.c
+++ b/drivers/net/smc9194.c
@@ -299,7 +299,8 @@
  . to store the packet, I call this routine, which either sends it
  . now, or generates an interrupt when the card is ready for the
  . packet */
-static int  smc_wait_to_send_packet( struct sk_buff * skb, struct net_device *dev );
+static netdev_tx_t  smc_wait_to_send_packet( struct sk_buff * skb,
+					     struct net_device *dev );
 
 /* this does a soft reset on the device */
 static void smc_reset( int ioaddr );
@@ -487,7 +488,8 @@
  . o 	(NO): Enable interrupts and let the interrupt handler deal with it.
  . o	(YES):Send it now.
 */
-static int smc_wait_to_send_packet( struct sk_buff * skb, struct net_device * dev )
+static netdev_tx_t smc_wait_to_send_packet(struct sk_buff *skb,
+					   struct net_device *dev)
 {
 	struct smc_local *lp = netdev_priv(dev);
 	unsigned int ioaddr 	= dev->base_addr;