Bluetooth: Simplify le_scan_disable_work()

Merge le_scan_disable_work_complete into the main le_scan_disable_work
function and take advantage of the updated bredr_inquiry() to run the
Inquiry through hci_req_sync().

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