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/ni65.c b/drivers/net/ni65.c
index 81a0617..752c2e4 100644
--- a/drivers/net/ni65.c
+++ b/drivers/net/ni65.c
@@ -252,7 +252,8 @@
 static int  ni65_open(struct net_device *dev);
 static int  ni65_lance_reinit(struct net_device *dev);
 static void ni65_init_lance(struct priv *p,unsigned char*,int,int);
-static int  ni65_send_packet(struct sk_buff *skb, struct net_device *dev);
+static netdev_tx_t ni65_send_packet(struct sk_buff *skb,
+				    struct net_device *dev);
 static void  ni65_timeout(struct net_device *dev);
 static int  ni65_close(struct net_device *dev);
 static int  ni65_alloc_buffer(struct net_device *dev);
@@ -1157,7 +1158,8 @@
  *	Send a packet
  */
 
-static int ni65_send_packet(struct sk_buff *skb, struct net_device *dev)
+static netdev_tx_t ni65_send_packet(struct sk_buff *skb,
+				    struct net_device *dev)
 {
 	struct priv *p = dev->ml_priv;