Bluetooth: Use hci_update_random_address() for initiating LE scan

When we start LE scanning we need to update the local random address if
necessary. This patch updates the code to use hci_update_random_address()
for setting the own_address_type scan parameter and updating the local
random address if necessary.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>