logic on checking timeout per operation is incorrect

After seeing the IllegalArgumentException in a log, I re-thought through the series of events here.

This flag on the op is known by user threads and the IO thread. Thus it
is modified in these two different ways:

• operation is created and enqueued
• OperationFuture is returned
• .get() is called on OF
  *timed out*

• operation is removed from input queue
• elapsed time is checked
  *timed out*