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/cs89x0.c b/drivers/net/cs89x0.c
index 839cac5..0c54219 100644
--- a/drivers/net/cs89x0.c
+++ b/drivers/net/cs89x0.c
@@ -246,7 +246,7 @@
 
 static int cs89x0_probe1(struct net_device *dev, int ioaddr, int modular);
 static int net_open(struct net_device *dev);
-static int net_send_packet(struct sk_buff *skb, struct net_device *dev);
+static netdev_tx_t net_send_packet(struct sk_buff *skb, struct net_device *dev);
 static irqreturn_t net_interrupt(int irq, void *dev_id);
 static void set_multicast_list(struct net_device *dev);
 static void net_timeout(struct net_device *dev);
@@ -1518,7 +1518,7 @@
 	netif_wake_queue(dev);
 }
 
-static int net_send_packet(struct sk_buff *skb, struct net_device *dev)
+static netdev_tx_t net_send_packet(struct sk_buff *skb,struct net_device *dev)
 {
 	struct net_local *lp = netdev_priv(dev);
 	unsigned long flags;