[NET]: Rework dev_base via list_head (v3)

Cleanup of dev_base list use, with the aim to simplify making device
list per-namespace. In almost every occasion, use of dev_base variable
and dev->next pointer could be easily replaced by for_each_netdev
loop. A few most complicated places were converted to using
first_netdev()/next_netdev().

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_ioctl.c b/net/bridge/br_ioctl.c
index eda0fbf..bb15e9e 100644
--- a/net/bridge/br_ioctl.c
+++ b/net/bridge/br_ioctl.c
@@ -27,7 +27,9 @@
 	struct net_device *dev;
 	int i = 0;
 
-	for (dev = dev_base; dev && i < num; dev = dev->next) {
+	for_each_netdev(dev) {
+		if (i >= num)
+			break;
 		if (dev->priv_flags & IFF_EBRIDGE)
 			indices[i++] = dev->ifindex;
 	}