Fix topology event sampling log directory

Run a topology and enable event inspection by clicking "Debug" from UI. The events are logged under "storm-local/workers-artifacts/

{storm-id}/port/events.log". In the spout/bolt details page, the "events" link does not display the log file.

The events.log should be kept under logs/workers-artifacts/{storm-id}

/

{port}

/events.log so that its viewable via logviewer.