If use docker attach command to attach to a stop container, it will return
"You cannot attach to a stopped container" error, it's ok, but when
attach to a running container, it(docker attach) use inspect to check
the container's state, if it pass the state check on the client side,
and then the container is stopped, docker attach command still attach to
the container and not exit.
Signed-off-by: Shukui Yang <yangshukui@huawei.com>
f9dc3337f9