Make struct CallBack indentation uniform again

Align the per-field comments.

Reviewed-on: http://gerrit.openafs.org/10929
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit cb4ec4e4952b40999013d4f67c0add6bf51ff286)

Change-Id: I9b388d03d9ca3da10eba6010147427b44a88d787
Reviewed-on: http://gerrit.openafs.org/10934
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Reviewed-by: D Brashear <shadow@your-file-system.com>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>