vp8: Fix compiler warning in vp8 pickinter.c
vp8: Fix compiler warning in vp8 pickinter.c

Change-Id: I0e5714538fe53d885a2201d808846901ae8fc288

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