netdev: convert pseudo drivers to netdev_tx_t

These are all drivers that don't touch real hardware.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c
index a42209a..d923d1d 100644
--- a/drivers/firewire/net.c
+++ b/drivers/firewire/net.c
@@ -1188,7 +1188,7 @@
 	return 0;
 }
 
-static int fwnet_tx(struct sk_buff *skb, struct net_device *net)
+static netdev_tx_t fwnet_tx(struct sk_buff *skb, struct net_device *net)
 {
 	struct fwnet_header hdr_buf;
 	struct fwnet_device *dev = netdev_priv(net);