Merge pull request #711 from yaazkal/fix-conf-zpool

[FIX] correctly use bastille_zfs_prefix to also work on pools != zroot

usr/local/etc/bastille/bastille.conf.sample

@@ -41,7 +41,7 @@ bastille_url_midnightbsd="https://www.midnightbsd.org/ftp/MidnightBSD/releases/"
 ## ZFS options
 bastille_zfs_enable="" ## default: ""
 bastille_zfs_zpool="" ## default: ""
-bastille_zfs_prefix="bastille"  ## default: "${bastille_zfs_zpool}/bastille"
+bastille_zfs_prefix="${bastille_zfs_zpool}/bastille" ## default: "${bastille_zfs_zpool}/bastille"
 bastille_zfs_options="-o compress=lz4 -o atime=off" ## default: "-o compress=lz4 -o atime=off"
 
 ## Export/Import options