ip6mr: fix rtm_family of rtnl msg

We talk about IPv6, hence the family is RTNL_FAMILY_IP6MR!
rtnl_register() is already called with RTNL_FAMILY_IP6MR.

The bug is here since the beginning of this function (commit 5b285cac).
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/ip6mr.c

@@ -2251,7 +2251,7 @@ static int ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb,
 		return -EMSGSIZE;
 
 	rtm = nlmsg_data(nlh);
-	rtm->rtm_family   = RTNL_FAMILY_IPMR;
+	rtm->rtm_family   = RTNL_FAMILY_IP6MR;
 	rtm->rtm_dst_len  = 128;
 	rtm->rtm_src_len  = 128;
 	rtm->rtm_tos      = 0;