vos: Show effects in single-volume dryrun mode

vos: Show effects in single-volume dryrun mode

Fix -dryrun mode for 'vos syncvldb' to also show the effects when run
against a specific volume id.

Change-Id: I3a2db96fc8016939f2f2f9561aba29527701ad59
Reviewed-on: http://gerrit.openafs.org/2667
Tested-by: Andrew Deason <adeason@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit e07f87070c901d71c2f4fa594738ce0a16c77ea1)
Reviewed-on: http://gerrit.openafs.org/2696