If the shim has been killed and ttrpc connection has been
closed, the shimErr will not be nil. For this case, the event
subscriber, like moby/moby, might have received the exit or delete
events. Just in case, we should allow ttrpc-callback-on-close to
send the exit and delete events again. And the exit status will
depend on result of shimV2.Delete.
If not, the shim has been delivered the exit and delete events.
So we should remove the task record and prevent duplicate events from
ttrpc-callback-on-close.
Fix: #4769
Signed-off-by: Wei Fu <fuweid89@gmail.com>
faec5d4ffd