ipv6: rt6_info output redirect to tunnel output

This is similar to ipv4 redirect of dst output to lwtunnel
output function for encapsulation and xmit.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index b3431b7..7f2214f 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1780,6 +1780,7 @@
 			goto out;
 		lwtunnel_state_get(lwtstate);
 		rt->rt6i_lwtstate = lwtstate;
+		rt->dst.output = lwtunnel_output6;
 	}
 
 	ipv6_addr_prefix(&rt->rt6i_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);