qcacld-3.0: Destroy logging thread irrespective of device mode
Presently the logging thread is not destroyed if the driver is unloaded
in the FTM mode leading to accessing to invalid memory location once
the wlan driver is unloaded.
Destroy the logging thread irrespective of the device mode during
the unload of the driver.
CRs-Fixed: 2040566
Change-Id: I1a97acffa5fb292ac9d355d6a95e6fc253fc833a