netfilter: xtables: fix incorrect return code

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

net/netfilter/xt_multiport.c

@@ -117,7 +117,7 @@ static int multiport_mt_check(const struct xt_mtchk_param *par)
 	const struct xt_multiport_v1 *multiinfo = par->matchinfo;
 
 	return check(ip->proto, ip->invflags, multiinfo->flags,
-		     multiinfo->count);
+		     multiinfo->count) ? 0 : -EINVAL;
 }
 
 static int multiport_mt6_check(const struct xt_mtchk_param *par)
@@ -126,7 +126,7 @@ static int multiport_mt6_check(const struct xt_mtchk_param *par)
 	const struct xt_multiport_v1 *multiinfo = par->matchinfo;
 
 	return check(ip->proto, ip->invflags, multiinfo->flags,
-		     multiinfo->count);
+		     multiinfo->count) ? 0 : -EINVAL;
 }
 
 static struct xt_match multiport_mt_reg[] __read_mostly = {