Make OpenAFS 1.8.9pre2

Make OpenAFS 1.8.9pre2

Update version strings for the second 1.8.9 prerelease.

Change-Id: Ic45d60180097f85263b2bd81b0beb039c36ad51f
Reviewed-on: https://gerrit.openafs.org/15192
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Cheyenne Wills <cwills@sinenomine.net>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>