[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/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
index cb3c6fa..457d81f 100644
--- a/drivers/net/bonding/bond_3ad.c
+++ b/drivers/net/bonding/bond_3ad.c
@@ -2429,7 +2429,7 @@
 	struct slave *slave = NULL;
 	int ret = NET_RX_DROP;
 
-	if (dev->nd_net != &init_net)
+	if (dev_net(dev) != &init_net)
 		goto out;
 
 	if (!(dev->flags & IFF_MASTER))
diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index b57bc94..b986dac 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -345,7 +345,7 @@
 	struct arp_pkt *arp = (struct arp_pkt *)skb->data;
 	int res = NET_RX_DROP;
 
-	if (bond_dev->nd_net != &init_net)
+	if (dev_net(bond_dev) != &init_net)
 		goto out;
 
 	if (!(bond_dev->flags & IFF_MASTER))
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 5fc9d8d58..ac688fc 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2629,7 +2629,7 @@
 	unsigned char *arp_ptr;
 	__be32 sip, tip;
 
-	if (dev->nd_net != &init_net)
+	if (dev_net(dev) != &init_net)
 		goto out;
 
 	if (!(dev->priv_flags & IFF_BONDING) || !(dev->flags & IFF_MASTER))
@@ -3470,7 +3470,7 @@
 {
 	struct net_device *event_dev = (struct net_device *)ptr;
 
-	if (event_dev->nd_net != &init_net)
+	if (dev_net(event_dev) != &init_net)
 		return NOTIFY_DONE;
 
 	dprintk("event_dev: %s, event: %lx\n",
@@ -3508,7 +3508,7 @@
 	struct bonding *bond, *bond_next;
 	struct vlan_entry *vlan, *vlan_next;
 
-	if (ifa->ifa_dev->dev->nd_net != &init_net)
+	if (dev_net(ifa->ifa_dev->dev) != &init_net)
 		return NOTIFY_DONE;
 
 	list_for_each_entry_safe(bond, bond_next, &bond_dev_list, bond_list) {