criu check: don't run as non-root

In case criu check is run as non-root, a lot of information is printed
to a user, with the only missing bit is it should run it as root.

Fix it.

I still don't like the fact that some other stuff is printed here,
like the timestamp and the __FILE__:__LINE__, but this should be
fixed separately.

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>