netfilter: nf_tables: flow event notifier must use transaction mutex

Fixes: f102d66b ("netfilter: nf_tables: use dedicated mutex to guard transactions")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_tables_api.c

@@ -5940,13 +5940,13 @@ static int nf_tables_flowtable_event(struct notifier_block *this,
 	if (!net)
 		return 0;
 
-	nfnl_lock(NFNL_SUBSYS_NFTABLES);
+	mutex_lock(&net->nft.commit_mutex);
 	list_for_each_entry(table, &net->nft.tables, list) {
 		list_for_each_entry(flowtable, &table->flowtables, list) {
 			nft_flowtable_event(event, dev, flowtable);
 		}
 	}
-	nfnl_unlock(NFNL_SUBSYS_NFTABLES);
+	mutex_unlock(&net->nft.commit_mutex);
 	put_net(net);
 	return NOTIFY_DONE;
 }