Bluetooth: Make use of __check_timeout on hci_sched_le

This reuse __check_timeout on hci_sched_le following the same logic
used hci_sched_acl.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>