Landlock support in setpriv(1)

Hi everybody,

For your information:

There is a proposal to add landlock support to setpriv(1) from
util-linux.
While landlock is meant for self-sandboxing it can also be used to
sandbox third party executables which makes it a nice fit for setpriv.

If you have any remarks let me know.

Link to the PR:
https://github.com/util-linux/util-linux/pull/2628


Thomas