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_sockaddr_pair_size(sa_family_t family)
{
	return PFKEY_ALIGN8(pfkey_sockaddr_len(family) * 2);
}

static int pfkey_sockaddr_pair_size(sa_family_t family)
{
	return PFKEY_ALIGN8(pfkey_sockaddr_len(family) * 2);
}
