Replacing raster_block with block in the encoder.

We only used "ib" to call get_scan() function, which in turn calls
get_tx_type_4x4() function. The latter one only needs block index if
bsize < BLOCK_8X8 -- under that condition raster_block == block.

Change-Id: I697306a0c3cf937acdd4f5e623d4367c5acc0b2f

vp9/encoder/vp9_encodemb.c

@@ -136,14 +136,13 @@ static void optimize_b(MACROBLOCK *mb,
   const int16_t *scan, *nb;
   const int mul = 1 + (tx_size == TX_32X32);
   uint8_t token_cache[1024];
-  const int ib = txfrm_block_to_raster_block(plane_bsize, tx_size, block);
   const int16_t *dequant_ptr = pd->dequant;
   const uint8_t *const band_translate = get_band_translate(tx_size);
 
   assert((!type && !plane) || (type && plane));
   dqcoeff_ptr = BLOCK_OFFSET(pd->dqcoeff, block);
   qcoeff_ptr = BLOCK_OFFSET(pd->qcoeff, block);
-  get_scan(xd, tx_size, type, ib, &scan, &nb);
+  get_scan(xd, tx_size, type, block, &scan, &nb);
   assert(eob <= default_eob);
 
   /* Now set up a Viterbi trellis to evaluate alternative roundings. */