af_key: initialize satype in key_notify_policy_flush()

This field was left uninitialized. Some user daemons perform check against this
field.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
static int pfkey_can_dump(const struct sock *sk)
{
	if (3 * atomic_read(&sk->sk_rmem_alloc) <= 2 * sk->sk_rcvbuf)
		return 1;
	return 0;
}

static int pfkey_can_dump(const struct sock *sk)
{
	if (3 * atomic_read(&sk->sk_rmem_alloc) <= 2 * sk->sk_rcvbuf)
		return 1;
	return 0;
}
