This commit addresses 2 issues:
1. in `tailfile()` if somehow the `logWatcher.Msg` were to become full and the watcher closed before space was made into it, we were getting stuck there forever since we were not checking for the watcher getting closed
2. when servicing `docker logs`, if the command was cancelled we were not closing the watcher (and hence notifying it to stop copying data)
Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>
Upstream-commit: fb2bb3653e2755d971f21debfecbd7c878a3c23f
Component: engine