netfilter: nf_tables: use correct lock to protect gc_list

jira VUlN-597
subsystem-sync netfilter:nf_tables 4.18.0-534
commit-author Pablo Neira Ayuso <pablo@netfilter.org>
commit 8357bc9

Use nf_tables_gc_list_lock spinlock, not nf_tables_destroy_list_lock to
protect the gc list.

Fixes: 5f68718 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
	Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
	Signed-off-by: Florian Westphal <fw@strlen.de>
(cherry picked from commit 8357bc9)
	Signed-off-by: Greg Rose <g.v.rose@ciq.com>

Author: gvrose8192

net/netfilter/nf_tables_api.c

@@ -7878,9 +7878,9 @@ static void nft_trans_gc_work(struct work_struct *work)
 	struct nft_trans_gc *trans, *next;
 	LIST_HEAD(trans_gc_list);
 
-	spin_lock(&nf_tables_destroy_list_lock);
+	spin_lock(&nf_tables_gc_list_lock);
 	list_splice_init(&nf_tables_gc_list, &trans_gc_list);
-	spin_unlock(&nf_tables_destroy_list_lock);
+	spin_unlock(&nf_tables_gc_list_lock);
 
 	list_for_each_entry_safe(trans, next, &trans_gc_list, list) {
 		list_del(&trans->list);