remove data access lock?

[tbrown122387]

Do we even need a lock on accessing the data? We're only reading from it here. We definitely need a lock on the counter and the thing we're writing to, but the input is shared across all function calls.

ssme/include/ssme/thread_pool.h

Lines 103 to 129 in a535e90

	void worker_thread() {
	while(!m_done)
	{
	if(m_has_an_input){
	// call the expensive function
	std::shared_lock<std::shared_mutex> param_lock(m_param_mut);
	func_output_t val = m_f(m_param, m_observed_data);
	// write it to the average and increment count
	// do this in thread-safe way with mutex
	std::lock_guard<std::mutex> out_lock{m_ac_mut};
	if( m_count.load() < m_total_calcs ) {
	m_working_ave += val / m_total_calcs;
	m_count++;
	}else if( m_count.load() == m_total_calcs){
	m_out.set_value(m_working_ave);
	m_has_an_input = false;
	m_count++;
	}
	}else{
	std::this_thread::yield();
	}
	}
	}