apparmor: fix display of .ns_name for containers

The .ns_name should not be virtualized by the current ns view. It
needs to report the ns base name as that is being used during startup
as part of determining apparmor policy namespace support.

BugLink: http://bugs.launchpad.net/bugs/1746463


Fixes: d9f02d9c ("apparmor: fix display of ns name")
Cc: Stable <stable@vger.kernel.org>
Reported-by: Serge Hallyn <serge@hallyn.com>
Tested-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>