bpf: eliminate rlimit-based memory accounting for xskmap maps

Do not use rlimit-based memory accounting for xskmap maps.
It has been replaced with the memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>

net/xdp/xskmap.c

@@ -74,7 +74,6 @@ static void xsk_map_sock_delete(struct xdp_sock *xs,
 
 static struct bpf_map *xsk_map_alloc(union bpf_attr *attr)
 {
-	struct bpf_map_memory mem;
 	int err, numa_node;
 	struct xsk_map *m;
 	u64 size;
@@ -90,18 +89,11 @@ static struct bpf_map *xsk_map_alloc(union bpf_attr *attr)
 	numa_node = bpf_map_attr_numa_node(attr);
 	size = struct_size(m, xsk_map, attr->max_entries);
 
-	err = bpf_map_charge_init(&mem, size);
-	if (err < 0)
-		return ERR_PTR(err);
-
 	m = bpf_map_area_alloc(size, numa_node);
-	if (!m) {
-		bpf_map_charge_finish(&mem);
+	if (!m)
 		return ERR_PTR(-ENOMEM);
-	}
 
 	bpf_map_init_from_attr(&m->map, attr);
-	bpf_map_charge_move(&m->map.memory, &mem);
 	spin_lock_init(&m->lock);
 
 	return &m->map;