[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_if.c b/net/bridge/br_if.c
index 690573b..849deaf 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -475,11 +475,9 @@
 	struct net_device *dev, *nxt;
 
 	rtnl_lock();
-	for (dev = dev_base; dev; dev = nxt) {
-		nxt = dev->next;
+	for_each_netdev_safe(dev, nxt)
 		if (dev->priv_flags & IFF_EBRIDGE)
 			del_br(dev->priv);
-	}
 	rtnl_unlock();
 
 }