* Move the device checks around
  Check in this order: DM-CRYPT, MD, LVM, ZFS
* Slight rewrite of the ZFS check
  + Zero the zfs_regexp - it's cumulative.
  + Catch values that can be 'n/a' now (not NULL any more).
  + Use previously set dmcrypt value so we don't have to go through the
    data again.
  + Catch LVM values (ZFS on LVM device).
  + Make sure that the device regexp is using word boundaries (don't
    catch 'test2' if we're looking for 'test').
  + Make sure we go through the zfs status including leading spaces.
  + It's "continue", not "shift" to skip lines in a while loop.
    Make sure we skip all the way to the dev header, not just five lines.
  + Smarter VDEV catch - using device as VDEV is possible.