netfilter: ipset: bitmap:ip,mac: fix listing with timeout

The type when timeout support was enabled, could not list all elements,
just the first ones which could fit into one netlink message: it just
did not continue listing after the first message.

Reported-by: Yoann JUET <yoann.juet@univ-nantes.fr>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Tested-by: Yoann JUET <yoann.juet@univ-nantes.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/ipset/ip_set_bitmap_ipmac.c

@@ -339,7 +339,11 @@ bitmap_ipmac_tlist(const struct ip_set *set,
 nla_put_failure:
 	nla_nest_cancel(skb, nested);
 	ipset_nest_end(skb, atd);
-	return -EMSGSIZE;
+	if (unlikely(id == first)) {
+		cb->args[2] = 0;
+		return -EMSGSIZE;
+	}
+	return 0;
 }
 
 static int