Fix a build error when ext-tx is off

Change-Id: I1cf27c41749c8f66eaa0ec828a1fd5d8ef7dd94e

av1/encoder/rdopt.c

@@ -5027,8 +5027,7 @@ static int64_t select_tx_size_fix_type(const AV1_COMP *cpi, MACROBLOCK *x,
   }
 #else
   if (mbmi->min_tx_size < TX_32X32 && !xd->lossless[xd->mi[0]->mbmi.segment_id])
-    rd_stats->rate +=
-        cpi->inter_tx_type_costs[mbmi->min_tx_size][mbmi->tx_type];
+    rd_stats->rate += x->inter_tx_type_costs[mbmi->min_tx_size][mbmi->tx_type];
 #endif  // CONFIG_EXT_TX
 #endif  // CONFIG_TXK_SEL