The value of loginuid cannot be changed inside container, with the
exception if it was not set yet. This value is inherited on fork() from
parent.

So, to restore original loginuid values for all tasks:
  - unset the container parent loginuid
  - all children will have this value unsetted
  - on child restore set value from dump

See http://lxr.free-electrons.com/source/kernel/audit.c#L635
https://jira.sw.ru/browse/PSBM-41993Signed-off-by: Dmitry Safonov <dsafonov@odin.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>