net: use NETDEV_TX_OK instead of 0 in ndo_start_xmit() functions

This patch is the result of an automatic spatch transformation to convert
all ndo_start_xmit() return values of 0 to NETDEV_TX_OK.

Some occurences are missed by the automatic conversion, those will be
handled in a seperate patch.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/irda/w83977af_ir.c

@@ -516,7 +516,7 @@ static int w83977af_hard_xmit(struct sk_buff *skb, struct net_device *dev)
 			w83977af_change_speed(self, speed); 
 			dev->trans_start = jiffies;
 			dev_kfree_skb(skb);
-			return 0;
+			return NETDEV_TX_OK;
 		} else
 			self->new_speed = speed;
 	}
@@ -576,7 +576,7 @@ static int w83977af_hard_xmit(struct sk_buff *skb, struct net_device *dev)
 	/* Restore set register */
 	outb(set, iobase+SSR);
 
-	return 0;
+	return NETDEV_TX_OK;
 }
 
 /*