selinux: fix warning in remove mode
an unintended side effect of d79c9623 is
that now a warning gets emitted from chroot_selinuxfs
in remove mode
when selinux is not in use.
a small adjustment avoids this, we just need to avoid running at all when selinux is not enabled, though i felt that it was sensible to allow remove mode to bypass this if it detects that installation occurred.
tested and works well.
Edited by Lyndon Brown