[Patch net-next] veth: add netpoll support

[Cong Wang <xiyou.wangcong@gmail.com>]

It is trivial to add netpoll support to veth, since
it is not stacked device, we don't need to setup and cleanup
netpoll.

Reported-by: Stefan Priebe <s.priebe@profihost.ag>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>

---
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index b4a10bc..03e781b 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -248,6 +248,13 @@ static void veth_dev_free(struct net_device *dev)
 	free_netdev(dev);
 }
 
+#ifdef CONFIG_NET_POLL_CONTROLLER
+static void veth_poll_controller(struct net_device *dev)
+{
+	return;
+}
+#endif	/* CONFIG_NET_POLL_CONTROLLER */
+
 static const struct net_device_ops veth_netdev_ops = {
 	.ndo_init            = veth_dev_init,
 	.ndo_open            = veth_open,
@@ -257,6 +264,9 @@ static const struct net_device_ops veth_netdev_ops = {
 	.ndo_get_stats64     = veth_get_stats64,
 	.ndo_set_rx_mode     = veth_set_multicast_list,
 	.ndo_set_mac_address = eth_mac_addr,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+	.ndo_poll_controller	= veth_poll_controller,
+#endif
 };
 
 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_ALL_TSO |    \