Fix the top-right reference block location

This commit fixes the top-right reference block location for block
sizes above 8x8. It improves the coding performance of ref-mv:

lowres 0.08%
midres 0.15%

Thanks to jiafeng@ for finding this issue.

Change-Id: I70750fc7b18bf0126d3e07abc1b63ca5a160193e

av1/common/mvref_common.c

@@ -394,8 +394,8 @@ static void setup_ref_mv_list(const AV1_COMMON *cm, const MACROBLOCKD *xd,
 
   // Check top-right boundary
   if (has_tr)
-    newmv_count += scan_blk_mbmi(cm, xd, mi_row, mi_col, block, rf, -1, 1,
+    newmv_count += scan_blk_mbmi(cm, xd, mi_row, mi_col, block, rf, -1,
-                                 ref_mv_stack, refmv_count);
+                                 xd->n8_w, ref_mv_stack, refmv_count);
 
   nearest_refmv_count = *refmv_count;