volscan: fix copyright and licence notice

These are new files and new content; fix the copyright notice and
license to reflect.

Reviewed-on: http://gerrit.openafs.org/11362
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit 1283226ccb638be47ead6cc4d9a47381aa6b08d1)

Change-Id: I4026bba6a10459ca0eb7b63666fe8e278949ca78
Reviewed-on: http://gerrit.openafs.org/11388
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>