Bluetooth: Clear non-persistent flags when closing HCI device

When hci_dev_do_close() is called we should make sure to clear all
non-persistent flags in hci->dev_flags.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>