* Zero out some variables before we check them. Last commit worked differently - it doesn't set a value if it can't be found.
* Faulty use of regexp in '[[ ... ]]' (removed ').
* If 'zpool status' or 'pvs' returns no values, remove the temp file directly.
* DM crypt requires both a mapper name AND a device.
* Increase the PVM column size.
* If ID_SCSI_COMPAT can't be found from udevadm output, try ID_ATA_COMPAT.
* Fix PVM check (smaller rewrites).
* Wrong variable used in DMCRYPT check.