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/net/phonet/pep-gprs.c b/net/phonet/pep-gprs.c
index 4667af5..d183509 100644
--- a/net/phonet/pep-gprs.c
+++ b/net/phonet/pep-gprs.c
@@ -183,7 +183,7 @@
 	return 0;
 }
 
-static int gprs_xmit(struct sk_buff *skb, struct net_device *dev)
+static netdev_tx_t gprs_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct gprs_dev *gp = netdev_priv(dev);
 	struct sock *sk = gp->sk;