HBSD: remove ZFS leftovers when WITHOUT_ZFS is set
tar tf base.txz | grep zpool
tar tf base.txz | grep zfs
tar tf base.txz | grep libbe
tar tf base.txz | grep bectl
note: libzfs.3 exists on 12-CURRENT and libzfs.2 exists before
12-CURRENT
Discussed-be: kevans@
MFC-to: 11-STABLE
Signed-off-by: Oliver Pinter <oliver.pinter@hardenedbsd.org>