Turn off adaptive_motion_search speed feature

This feature breaks encoder multi-thread tests.
The values in x->pred_mv[] differ for single and multi-thread cases.

BUG=aomedia:1778

Change-Id: I61f17240d5385392dd6ef652644566f2f7514e4b
diff --git a/av1/encoder/speed_features.c b/av1/encoder/speed_features.c
index 5a9c80f..9788e7b 100644
--- a/av1/encoder/speed_features.c
+++ b/av1/encoder/speed_features.c
@@ -184,7 +184,10 @@
     sf->less_rectangular_check = 1;
     sf->mode_skip_start = 10;
     sf->adaptive_pred_interp_filter = 1;
-    sf->adaptive_motion_search = 1;
+    // adaptive_motion_search breaks encoder multi-thread tests.
+    // The values in x->pred_mv[] differ for single and multi-thread cases.
+    // See aomedia:1778.
+    // sf->adaptive_motion_search = 1;
     sf->recode_loop = ALLOW_RECODE_KFARFGF;
     sf->use_transform_domain_distortion = 1;
     sf->use_accurate_subpel_search = 0;
@@ -328,7 +331,7 @@
 
   if (speed & INTER_PRED_SF) {
     sf->selective_ref_frame = 2;
-    sf->adaptive_motion_search = 1;
+    // sf->adaptive_motion_search = 1;
     sf->mv.auto_mv_step_size = 1;
     sf->adaptive_rd_thresh = 1;
     sf->mv.subpel_iters_per_step = 1;