security_util: Remove stale XATTRs
It may happen that we leave some XATTRs behind. For instance, on
a sudden power loss, the host just shuts down without calling
restore on domain paths. This creates a problem, because when the
host starts up again, the XATTRs are there but they don't reflect
the true state and this may result in libvirt denying start of a
domain.
To solve this, save a unique timestamp (host boot time) among
with our XATTRs.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=
1741140
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>