WifiSupplicantControl: Add missing null check for psk
am: c7ddffabcd

Change-Id: Iabd056ff2cb3515acc1f24bf47f637b3cdbe3fa3
tree: d2562df5abc939b5926e7e3550829c49f17efa8e
  1. libwifi_hal/
  2. libwifi_system/
  3. service/
  4. tests/
  5. PREUPLOAD.cfg