wg_peer_get_maybe_zero
peer = wg_peer_get_maybe_zero(rcu_dereference_bh(node->peer));
struct wg_peer *__must_check wg_peer_get_maybe_zero(struct wg_peer *peer);
entry->peer = wg_peer_get_maybe_zero(entry->peer);
peer = wg_peer_get_maybe_zero(peer);