Currenlty if criu fails before prepare_cgroup_properties(),
cgyard isn't umounted.

I think it's déjà vu, but it isn't :)

commit 28b0e16d
Author: Andrew Vagin <avagin@openvz.org>
Date:   Mon Aug 25 14:29:00 2014 +0400

    cgroup: call fin_cgroup() on error paths

Cc: Tycho Andersen <tycho.andersen@canonical.com>
Cc: Saied Kazemi <saied@google.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>