lwt: Add cfg argument to build_state

Add cfg and family arguments to lwt build state functions. cfg is a void
pointer and will either be a pointer to a fib_config or fib6_config
structure. The family parameter indicates which one (either AF_INET
or AF_INET6).

LWT encpasulation implementation may use the fib configuration to build
the LWT state.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index e476f01..df3e353 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1819,7 +1819,8 @@
 		struct lwtunnel_state *lwtstate;
 
 		err = lwtunnel_build_state(dev, cfg->fc_encap_type,
-					   cfg->fc_encap, &lwtstate);
+					   cfg->fc_encap, AF_INET6, cfg,
+					   &lwtstate);
 		if (err)
 			goto out;
 		rt->dst.lwtstate = lwtstate_get(lwtstate);