A fix for a missing tx_type

Change-Id: I165cd06256175edb7739020379ba3098251f4a7c

vp10/encoder/rdopt.c

diff --git a/vp10/encoder/rdopt.c b/vp10/encoder/rdopt.c
index b55f53a..defe999 100644
--- a/vp10/encoder/rdopt.c
+++ b/vp10/encoder/rdopt.c
@@ -961,6 +961,7 @@
   MB_MODE_INFO *const mbmi = &xd->mi[0]->mbmi;
 
   mbmi->tx_size = TX_4X4;
+  mbmi->tx_type = DCT_DCT;
 
   txfm_rd_in_plane(x,
 #if CONFIG_VAR_TX