Also add an extra check in BindBufferBase/Range that XFB is not active.

BUG=angle:898

Change-Id: I0d61ebaa0674b0a375cc35efa614b021a6901eac
Reviewed-on: https://chromium-review.googlesource.com/243892Tested-by: Gregoire Payen de La Garanderie <Gregory.Payen@imgtec.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>