netfilter: nfnetlink: remove static declaration from err_list

Otherwise, different subsys will race to access the err_list, with holding
the different nfnl_lock(subsys_id).

But this will not happen now, since ->call_batch is only implemented by
nftables, so the err_list is protected by nfnl_lock(NFNL_SUBSYS_NFTABLES).
Signed-off-by: NLiping Zhang <zlpnobody@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nfnetlink.c

@@ -279,7 +279,7 @@ static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh,
 	struct net *net = sock_net(skb->sk);
 	const struct nfnetlink_subsystem *ss;
 	const struct nfnl_callback *nc;
-	static LIST_HEAD(err_list);
+	LIST_HEAD(err_list);
 	u32 status;
 	int err;