FM: synchronize mReceiver object

  - synchronize mReceiver object to prevent null object 
    access while fm on/off stablity test.
  - fix is needed in fm on sequence, since we setting 
    mReceiver object to null while disabling.
    in race condition where multiple fm on/off performed
    mReceiver can be null.

Change-Id: I6dd67958b40146ff48ce521e06ecb246e3fd1307
1 file changed
tree: fbbe091f420a60faef3fb011ea768dc2a8ff8712
  1. fm_hci/
  2. fmapp2/
  3. helium/
  4. jni/
  5. qcom/
  6. Android.mk