MB_MODE_INFO is a 4x4 unit?

Change-Id: Idc1dfe087da412ee10d8a8be9c570a1d8038d9a7
diff --git a/av1/common/onyxc_int.h b/av1/common/onyxc_int.h
index 9578110..d6e1b5e 100644
--- a/av1/common/onyxc_int.h
+++ b/av1/common/onyxc_int.h
@@ -373,7 +373,7 @@
   int allow_warped_motion;
 
   // MBs, mb_rows/cols is in 16-pixel units; mi_rows/cols is in
-  // MB_MODE_INFO (8-pixel) units.
+  // MB_MODE_INFO (4-pixel) units.
   int MBs;
   int mb_rows, mi_rows;
   int mb_cols, mi_cols;