Bluetooth: Restore running state if suspend fails

If Bluetooth fails to enter the suspended state correctly, restore the
state to running (re-enabling scans). PM_POST_SUSPEND is only sent to
notifiers that successfully return from PM_PREPARE_SUSPEND notification
so we should recover gracefully if it fails.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>