audio: free and assign NULL to global static device pointer am: 506fd42a89

Change-Id: Ie5298d1d83de872c5a2eb64c35ca2a8fcfac0c75
tree: eaa3103cea79aeb1b0aaa53e65e7c33fd50fd2bb
  1. hal/
  2. legacy/
  3. post_proc/
  4. visualizer/
  5. voice_processing/
  6. Android.mk
  7. OWNERS