netfilter: ebtables: put module reference when an incorrect extension is found

commit bcf493428840 ("netfilter: ebtables: Fix extension lookup with
identical name") added a second lookup in case the extension that was
found during the first lookup matched another extension with the same
name, but didn't release the reference on the incorrect module.

Fixes: bcf493428840 ("netfilter: ebtables: Fix extension lookup with identical name")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/bridge/netfilter/ebtables.c

@@ -368,6 +368,8 @@ ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
 
 	match = xt_find_match(NFPROTO_BRIDGE, m->u.name, 0);
 	if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) {
+		if (!IS_ERR(match))
+			module_put(match->me);
 		request_module("ebt_%s", m->u.name);
 		match = xt_find_match(NFPROTO_BRIDGE, m->u.name, 0);
 	}