netns: move net->ipv4.rt_genid to net->rt_genid

This commit prepares the use of rt_genid by both IPv4 and IPv6.
Initialization is left in IPv4 part.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index ae1cd6c..fd87963 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -102,6 +102,7 @@
 #endif
 	struct netns_ipvs	*ipvs;
 	struct sock		*diag_nlsk;
+	atomic_t		rt_genid;
 };
 
 
@@ -300,5 +301,14 @@
 }
 #endif
 
+static inline int rt_genid(struct net *net)
+{
+	return atomic_read(&net->rt_genid);
+}
+
+static inline void rt_genid_bump(struct net *net)
+{
+	atomic_inc(&net->rt_genid);
+}
 
 #endif /* __NET_NET_NAMESPACE_H */