Remove unnecessary calls to load_pred_mv()
Remove unnecessary calls to load_pred_mv()

This improves compression performance slightly:
Speed 1:
         avg_psnr   ovr_psnr   ssim
lowres   -0.03%     -0.03%    -0.05%
midres   -0.16%     -0.20%    -0.30%
hdres    -0.13%     -0.13%    -0.16%

Speed 2:
         avg_psnr   ovr_psnr   ssim
lowres   -0.02%     -0.02%    -0.03%
midres   -0.08%     -0.06%    -0.10%
hdres    -0.08%     -0.08%    -0.10%

Change-Id: Id357c1f98042f3c7af56f99e534bc81ea9a7cf36

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