Fetch the actually running selinux status.

Fetch the actually running selinux status.

The HostFacts should return the **actual** selinux mode in which the
kernel is running.

The actual mode can be different from the one in the configuration
if the server has not been rebooted or if the mode was changed
after boot using setenforce.

Instead of reading _selinux_path_list we should look at the output of
sestatus or getenforce.

The _selinux_path_list attribute is no longer needed.

Fixes: https://tracker.ceph.com/issues/51632
Signed-off-by: Javier Cacheiro <javier.cacheiro.lopez@cesga.es>