vos clone  use the value of the -toname argument

The -toname argument was not followed with the vos clone command. The name
of the clone volume was always ".clone".

Change-Id: I76b78d239ecb38e793098078ac34a703f2ffeeeb
Reviewed-on: http://gerrit.openafs.org/11431
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: D Brashear <shadow@your-file-system.com>