netfilter: nf_tables: fix wrong destroy anonymous sets if binding fails

When we add a nft rule like follows:
  # nft add rule filter test tcp dport vmap {1: jump test}
-ELOOP error will be returned, and the anonymous set will be
destroyed.

But after that, nf_tables_abort will also try to remove the
element and destroy the set, which was already destroyed and
freed.

If we add a nft wrong rule, nft_tables_abort will do the cleanup
work rightly, so nf_tables_set_destroy call here is redundant and
wrong, remove it.
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_tables_api.c

@@ -2958,14 +2958,9 @@ int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,
 		iter.fn		= nf_tables_bind_check_setelem;
 
 		set->ops->walk(ctx, set, &iter);
-		if (iter.err < 0) {
-			/* Destroy anonymous sets if binding fails */
-			if (set->flags & NFT_SET_ANONYMOUS)
-				nf_tables_set_destroy(ctx, set);
-
+		if (iter.err < 0)
 			return iter.err;
 	}
-	}
 bind:
 	binding->chain = ctx->chain;
 	list_add_tail_rcu(&binding->list, &set->bindings);