[ENHANCEMENT] Alternative default bastille_zfs_prefix

[MamoruDS]

Is your feature request related to a problem? Please describe.

The current default value of bastille_zfs_prefix has been changed(#711) to ${bastille_zfs_zpool}/bastille. Since all the scripts use ${bastille_zfs_zpool}/${bastille_zfs_prefix} as the dataset path prefix, this causes a duplication of bastille_zfs_zpool (which will be zroot/zroot/bastille after setup without any modification).

Describe the solution you'd like

To avoid this issue, manually change the config value of bastille_zfs_prefix to an arbitrary value (e.g., the previous bastille). Reverting to bastille as the default may provide a smoother experience.

Additional context

An example in bootstrap.sh shows the script using ${bastille_zfs_zpool}/${bastille_zfs_prefix} as the dataset path:

https://github.com/BastilleBSD/bastille/blame/cee6f20aa5c228e7e4791bc9d0fcdc412bab71ae/usr/local/share/bastille/bootstrap.sh#L150

[yaazkal]

Thanks for the comment and the workaround, I'm gonna take this