bpf: Eliminate rlimit-based memory accounting for lpm_trie maps

Do not use rlimit-based memory accounting for lpm_trie maps.
It has been replaced with the memcg-based memory accounting.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-25-guro@fb.com

kernel/bpf/lpm_trie.c

@@ -540,8 +540,6 @@ static int trie_delete_elem(struct bpf_map *map, void *_key)
 static struct bpf_map *trie_alloc(union bpf_attr *attr)
 {
 	struct lpm_trie *trie;
-	u64 cost = sizeof(*trie), cost_per_node;
-	int ret;
 
 	if (!bpf_capable())
 		return ERR_PTR(-EPERM);
@@ -567,20 +565,9 @@ static struct bpf_map *trie_alloc(union bpf_attr *attr)
 			  offsetof(struct bpf_lpm_trie_key, data);
 	trie->max_prefixlen = trie->data_size * 8;
 
-	cost_per_node = sizeof(struct lpm_trie_node) +
-			attr->value_size + trie->data_size;
-	cost += (u64) attr->max_entries * cost_per_node;
-
-	ret = bpf_map_charge_init(&trie->map.memory, cost);
-	if (ret)
-		goto out_err;
-
 	spin_lock_init(&trie->lock);
 
 	return &trie->map;
-out_err:
-	kfree(trie);
-	return ERR_PTR(ret);
 }
 
 static void trie_free(struct bpf_map *map)