Simplify the if clause in define_gf_group
Simplify the if clause in define_gf_group

Change-Id: I70a06a4f48c5a215831d8b6e918eebc3041ef65a

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