netfilter: xt_limit: fix invalid return code in limit_mt_check()

Commit acc738fe (netfilter: xtables: avoid pointer to self) introduced
an invalid return value in limit_mt_check().

Signed-off-by: Patrick McHardy <kaber@trash.net>

net/netfilter/xt_limit.c

@@ -112,7 +112,7 @@ static bool limit_mt_check(const struct xt_mtchk_param *par)
 
 	priv = kmalloc(sizeof(*priv), GFP_KERNEL);
 	if (priv == NULL)
-		return -ENOMEM;
+		return false;
 
 	/* For SMP, we only want to use one set of state. */
 	r->master = priv;