Do not supply UUID to diskarbitration.

Removing handling of '-k' option to the probe executable.
OS X wants something in the format:

    XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX

Even providing a UUID in that format still confuses
Spotlight, though. At least by refusing to handle
'-k' Spotlight can be enabled on the child file systems.

Perhaps this can be restored if Spotlight issues are
addressed first.