netfilter: ipset: restore allowing 64 clashing elements in hash:net,iface

The commit 510841da1f ("netfilter: ipset: enforce documented limit to
prevent allocating huge memory") was too strict and prevented to add up to
64 clashing elements to a hash:net,iface type of set. This patch fixes the
issue and now the type behaves as documented.

Fixes: 510841da1f ("netfilter: ipset: enforce documented limit to prevent allocating huge memory")
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/ipset/ip_set_hash_gen.h

@@ -916,7 +916,7 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext,
 #ifdef IP_SET_HASH_WITH_MULTI
 		if (h->bucketsize >= AHASH_MAX_TUNED)
 			goto set_full;
-		else if (h->bucketsize < multi)
+		else if (h->bucketsize <= multi)
 			h->bucketsize += AHASH_INIT_SIZE;
 #endif
 		if (n->size >= AHASH_MAX(h)) {