[NETNS]: Process FIB rule action in the context of the namespace.

Save namespace context on the fib rule at the rule creation time and
call routing lookup in the correct namespace.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h
index 7f9f4ae..34349f9 100644
--- a/include/net/fib_rules.h
+++ b/include/net/fib_rules.h
@@ -22,6 +22,7 @@
 	u32			target;
 	struct fib_rule *	ctarget;
 	struct rcu_head		rcu;
+	struct net *		fr_net;
 };
 
 struct fib_lookup_arg