Windows: Add Cell to FS Volume Information Label

Windows: Add Cell to FS Volume Information Label

Add the Cell name to the VolumeLabel field of the
FILE_FS_VOLUME_INFORMATION structure.  This permits "cell#volume" to be
displayed by cmd.exe's DIR command and other applications that call the
GetVolumeInformation() or GetVolumeInformationByHandle() Win32 APIs.

Change-Id: I6cc7a7c2b79cb7d0d96cbddcf34dce68e52bf987
Reviewed-on: http://gerrit.openafs.org/9106
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>