Fix the bug that PVQ commit broke dering

Since PVQ's max block size equals to the max transform size,
daala's definition of OD_BSIZE_MAX was changed from 5 down to 4 to
use AV1's max trasform size 32x32. However, dering also uses
OD_BSIZE_MAX and assumes its value is 5, which caused dering
not working.

Change-Id: I9d82bb24adc7d57552a8e0a8a7e798e77d96fd4b
diff --git a/av1/common/pvq_state.c b/av1/common/pvq_state.c
index 45d5184..2329d66 100644
--- a/av1/common/pvq_state.c
+++ b/av1/common/pvq_state.c
@@ -20,7 +20,7 @@
   OD_CDFS_INIT(adapt->skip_cdf, adapt->skip_increment >> 2);
   for (pli = 0; pli < OD_NPLANES_MAX; pli++) {
     generic_model_init(&adapt->model_dc[pli]);
-    for (i = 0; i < OD_NBSIZES; i++) {
+    for (i = 0; i < OD_TXSIZES; i++) {
       adapt->ex_g[pli][i] = 8;
     }
     for (i = 0; i < 4; i++) {