predict_test: align dst buffer to 16
predict_test: align dst buffer to 16

On 32 bit machines 'new' does not always appear to allocate sufficiently
aligned buffers, causing intermittent test failures.

Change-Id: I0db4fc73782012e4eef71dc0fb540e74fdbfcebe

mwgoldsmith/vpx,webmproject/libvpx,Topopiccione/libvpx,mwgoldsmith/vpx,mwgoldsmith/vpx,mwgoldsmith/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,webmproject/libvpx,Topopiccione/libvpx,mwgoldsmith/libvpx,mwgoldsmith/libvpx,Topopiccione/libvpx,Topopiccione/libvpx,mwgoldsmith/vpx,webmproject/libvpx,webmproject/libvpx,Topopiccione/libvpx,mwgoldsmith/vpx,ShiftMediaProject/libvpx,mwgoldsmith/libvpx,mwgoldsmith/libvpx,ShiftMediaProject/libvpx,Topopiccione/libvpx,ShiftMediaProject/libvpx,mwgoldsmith/libvpx,ShiftMediaProject/libvpx,mwgoldsmith/vpx,webmproject/libvpx