[VLAN]: Introduce the vlan_net structure and init/exit net ops.

Unlike TUN, it is empty from the very beginning, and will 
be eventually populated later.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/8021q/vlan.h b/net/8021q/vlan.h
index 51271ae..f27d8d6 100644
--- a/net/8021q/vlan.h
+++ b/net/8021q/vlan.h
@@ -50,4 +50,9 @@
 	return dev->priv_flags & IFF_802_1Q_VLAN;
 }
 
+extern int vlan_net_id;
+
+struct vlan_net {
+};
+
 #endif /* !(__BEN_VLAN_802_1Q_INC__) */