volinfo: print errors to stderr

volinfo: print errors to stderr

Print volinfo errors messages to stderr instead of a mix of stdout
and stderr. Print a consistent program name.

Reviewed-on: http://gerrit.openafs.org/4693
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit b7fe087745923bdea4571870799e484da67221d2)

Change-Id: Id9b6eb5c0cb50bc3908d6e1662f4485219452ecc
Reviewed-on: http://gerrit.openafs.org/11246
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>