message: Fix incorrect logging in ThreadPlan::ShouldReportStop
  it used printf with formatv style specifications. Also, switch to
  LLDB_LOG.
diff: @@ -76,14 +76,11 @@ Vote ThreadPlan::ShouldReportStop(Event *event_ptr) {
  ThreadPlan *prev_plan = GetPreviousPlan();
  if (prev_plan) {
  Vote prev_vote = prev_plan->ShouldReportStop(event_ptr);
  - if (log)
  - log->Format(__FILE__, __FUNCTION__,
  - "returning previous thread plan vote: {0}", prev_vote);
  + LLDB_LOG(log, "returning previous thread plan vote: {0}", prev_vote);
  return prev_vote;
  }
  }
  - if (log)
  - log->Printf("Returning vote: {0}", m_stop_vote);
  + LLDB_LOG(log, "Returning vote: {0}", m_stop_vote);
  return m_stop_vote;
  }
  