Properly reset memory in hbd setting
Properly reset memory in hbd setting

This avoids a segmentation failure issue in high bit-depth case.

Change-Id: I9fbb3ec24b1735678f110cb084a29b15e3ec1a12

ShiftMediaProject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx