vp9: Move allocation of vt2 after early exits.
vp9: Move allocation of vt2 after early exits.

Remove the memory deallocation on the early exits.

Change-Id: I00b4a814ae6705105ecab89644d055ca3311d9f4

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