get_tx_type: remove dead store

w/ !(FIXED_TX_TYPE || CONFIG_EXT_TX)

BUG=aomedia:445

Change-Id: I4e9e531f1983656030c61d823e16f7704b89cfdd
diff --git a/av1/common/blockd.h b/av1/common/blockd.h
index cb17826..ec3b975 100644
--- a/av1/common/blockd.h
+++ b/av1/common/blockd.h
@@ -953,11 +953,11 @@
   if (is_intrabc_block(mbmi)) return DCT_DCT;
 #endif  // CONFIG_INTRABC
 #if !CONFIG_TXK_SEL
+#if FIXED_TX_TYPE
   const int block_raster_idx = av1_block_index_to_raster_order(tx_size, block);
-  if (FIXED_TX_TYPE)
-    return get_default_tx_type(plane_type, xd, block_raster_idx, tx_size);
-
-#if CONFIG_EXT_TX
+  return get_default_tx_type(plane_type, xd, block_raster_idx, tx_size);
+#elif CONFIG_EXT_TX
+  const int block_raster_idx = av1_block_index_to_raster_order(tx_size, block);
   if (xd->lossless[mbmi->segment_id] || txsize_sqr_map[tx_size] > TX_32X32 ||
       (txsize_sqr_map[tx_size] >= TX_32X32 && !is_inter_block(mbmi)))
     return DCT_DCT;