containerd: Define a local struct as result of adapter.inspect()
containerd: Define a local struct as result of adapter.inspect()

The containerd Task struct contains a lot of info which callers are not
interested in and which is not provided by the Task.Status() method, which we
will shortly switch to in preference to an open coded InfoRequest gRPC.

Belt-and-braces checks that ID and Pid match will go away as part of
Task.Status switch.

Signed-off-by: Ian Campbell <9be92b3dbbd6611e3e4c9209fb3d04b4919e7cca@docker.com>

alyyousuf7/swarmkit,jlhawn/swarmkit,dperny/swarmkit-1,sungwonh/swarmkit,cheyang/swarmkit,Noyan759/swarmkit,sungwonh/swarmkit,RenaudWasTaken/swarmkit,dperny/swarmkit-1,AliyunContainerService/swarmkit,docker/swarmkit,AliyunContainerService/swarmkit,docker/swarmkit,jlhawn/swarmkit,cheyang/swarmkit,alyyousuf7/swarmkit,Noyan759/swarmkit,RenaudWasTaken/swarmkit