[NET] NETNS: Omit net_device->nd_net without CONFIG_NET_NS.

Introduce per-net_device inlines: dev_net(), dev_net_set().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
diff --git a/drivers/net/wan/dlci.c b/drivers/net/wan/dlci.c
index 96b2324..b142427 100644
--- a/drivers/net/wan/dlci.c
+++ b/drivers/net/wan/dlci.c
@@ -517,7 +517,7 @@
 {
 	struct net_device *dev = (struct net_device *) ptr;
 
-	if (dev->nd_net != &init_net)
+	if (dev_net(dev) != &init_net)
 		return NOTIFY_DONE;
 
 	if (event == NETDEV_UNREGISTER) {
diff --git a/drivers/net/wan/hdlc.c b/drivers/net/wan/hdlc.c
index 39951d0..9a83c9d 100644
--- a/drivers/net/wan/hdlc.c
+++ b/drivers/net/wan/hdlc.c
@@ -68,7 +68,7 @@
 {
 	struct hdlc_device *hdlc = dev_to_hdlc(dev);
 
-	if (dev->nd_net != &init_net) {
+	if (dev_net(dev) != &init_net) {
 		kfree_skb(skb);
 		return 0;
 	}
@@ -105,7 +105,7 @@
 	unsigned long flags;
 	int on;
  
-	if (dev->nd_net != &init_net)
+	if (dev_net(dev) != &init_net)
 		return NOTIFY_DONE;
 
 	if (dev->get_stats != hdlc_get_stats)
diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c
index fb37b80..629c909 100644
--- a/drivers/net/wan/lapbether.c
+++ b/drivers/net/wan/lapbether.c
@@ -91,7 +91,7 @@
 	int len, err;
 	struct lapbethdev *lapbeth;
 
-	if (dev->nd_net != &init_net)
+	if (dev_net(dev) != &init_net)
 		goto drop;
 
 	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
@@ -393,7 +393,7 @@
 	struct lapbethdev *lapbeth;
 	struct net_device *dev = ptr;
 
-	if (dev->nd_net != &init_net)
+	if (dev_net(dev) != &init_net)
 		return NOTIFY_DONE;
 
 	if (!dev_is_ethdev(dev))
diff --git a/drivers/net/wan/syncppp.c b/drivers/net/wan/syncppp.c
index 61e24b7..29b4b94 100644
--- a/drivers/net/wan/syncppp.c
+++ b/drivers/net/wan/syncppp.c
@@ -1444,7 +1444,7 @@
 
 static int sppp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *p, struct net_device *orig_dev)
 {
-	if (dev->nd_net != &init_net) {
+	if (dev_net(dev) != &init_net) {
 		kfree_skb(skb);
 		return 0;
 	}