gst-validate-scenario: Fix (another) race condition in EOS handling
Since gst_validate_action_set_done() is asynchronous, the bus EOS handler may already be running before the action is actually finished. This patch ensures that is not a problem.
Since gst_validate_action_set_done() is asynchronous, the bus EOS handler may already be running before the action is actually finished. This patch ensures that is not a problem.