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 void pfkey_remove(struct sock *sk)
{
	mutex_lock(&pfkey_mutex);
	sk_del_node_init_rcu(sk);
	mutex_unlock(&pfkey_mutex);
}

static void pfkey_remove(struct sock *sk)
{
	mutex_lock(&pfkey_mutex);
	sk_del_node_init_rcu(sk);
	mutex_unlock(&pfkey_mutex);
}
