Merge branch 'vmwgfx-fixes-3.16' of git://people.freedesktop.org/~thomash/linux

fix to a 3.15 commit.

* 'vmwgfx-fixes-3.16' of git://people.freedesktop.org/~thomash/linux:
  drm/vmwgfx: Fix incorrect write to read-only register v2: