redhat: fix rpmbuild warnings

redhat: fix rpmbuild warnings

Fix warnings issued by recent versions of rpmbuild:

    warning: Macro expanded in comment on line 110: %{afsvers}/...
    warning: extra tokens at the end of %endif directive in line 1469:
             %endif  # build_userspace
    warning: line 331: It's not recommended to have unversioned Obsoletes:
             Obsoletes: openafs-client-compat

The first two warnings are just issues with comments, which apparently
are not completely ignored by rpmbuild.  The third issue is a warning
about an unversioned "Obsoletes" directive. Remove the old Obsoletes for
openafs-client-compat, which was obsoleted no later than the 1.4.x
series (more than 10 years ago).

While here clean up the spec by removing the old cvs $Revsion$ keyword
from the comments at the top of the file, and removing an old commented
out setup directive.

Change-Id: I8d7a050ea6a0cc7a2d9a6af9a91d25ce545586e7
Reviewed-on: https://gerrit.openafs.org/14118
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>