Limit the reset range of inter_tx_size array

Reset the effective range of inter_tx_size, instead of the entire
array in the rate-distortion optimization loop.

Change-Id: Id453fbd6dddfe69f4e451ba8518c083326d5dd53
diff --git a/vp10/encoder/rdopt.c b/vp10/encoder/rdopt.c
index 5c447b2..f31917a 100644
--- a/vp10/encoder/rdopt.c
+++ b/vp10/encoder/rdopt.c
@@ -4277,10 +4277,12 @@
                       bsize, ref_best_rd);
 #endif
     } else {
+      int idx, idy;
       super_block_yrd(cpi, x, rate_y, &distortion_y, &skippable_y, psse,
                       bsize, ref_best_rd);
-      for (i = 0; i < 64; ++i)
-        mbmi->inter_tx_size[i] = mbmi->tx_size;
+      for (idy = 0; idy < xd->n8_h; ++idy)
+        for (idx = 0; idx < xd->n8_w; ++idx)
+          mbmi->inter_tx_size[idy * 8 + idx] = mbmi->tx_size;
     }
 #else
     super_block_yrd(cpi, x, rate_y, &distortion_y, &skippable_y, psse,
@@ -5549,8 +5551,7 @@
     }
 
 #if CONFIG_VAR_TX
-    for (i = 0; i < 64; ++i)
-      mbmi->inter_tx_size[i] = mbmi->tx_size;
+    mbmi->inter_tx_size[0] = mbmi->tx_size;
 #endif
 
     if (ref_frame == INTRA_FRAME) {