This patch fixes a regression introduced in 1d190950 where the encoder
 was using the 16x16 VP9/AV1 transforms for RDO, but then used the Daala
 transforms for encoding.

subset1:

master-daala_dct16@2017-09-13T12:05:18.013Z ->
  master_daala_dct16_use_c@2017-09-13T13:05:02.252Z

   PSNR | PSNR Cb | PSNR Cr | PSNR HVS |    SSIM | MS SSIM | CIEDE 2000
-0.3654 | -0.7634 | -0.7407 |  -0.4884 | -0.4699 | -0.4945 |    -0.5104

master-no_rect_tx-no_var_tx@2017-09-12T00:23:18.153Z ->
  master_daala_dct16_use_c@2017-09-13T13:05:02.252Z

   PSNR | PSNR Cb | PSNR Cr | PSNR HVS |    SSIM | MS SSIM | CIEDE 2000
-0.0133 |  0.1040 | -0.0440 |  -0.0492 | -0.0151 | -0.0120 |     0.0699

Change-Id: Id1830d0975db4bd0320a47fdf45b4bca20881cfb