Revert "Merge "Change highbd variance rounding to prevent negative variance.""

This reverts commit ea48370a500537906d62544ca4ed75301d79e772, reversing
changes made to 15939cb2d76c773950cda40988ede89e111872ea.

The commit was insufficiently tested and causes failures.

Change-Id: I623d6fc2cd3ae6fd42d0abab1f8eada465ae57a7
4 files changed