On disconnecting, the bssid may not be filled in cm_req->discon_req.
Zero bssid will fail to update the scan entry to non association
state which may block the scan entry age out.
Move disconnect bssid fill before update the scan entry for
disconnecting.
Change-Id: Id8a36d8a37c212af727c7b61a24b51f2782c4a2c
CRs-Fixed: 3291599