sound.cpp: Perform the sanity check from a0137c1 in a better place (n…

…w, seems to fix assert error)

src/emu/sound.cpp

@@ -268,9 +268,6 @@ void sound_stream::update()
 	attotime time = m_device.machine().time();
 	s32 update_sampindex = s32(time.attoseconds() / m_attoseconds_per_sample);
 
-	if (update_sampindex <= m_output_sampindex)
-		return;
-
 	// if we're ahead of the last update, then adjust upwards
 	attotime last_update = m_device.machine().sound().last_update();
 	if (time.seconds() > last_update.seconds())
@@ -286,6 +283,9 @@ void sound_stream::update()
 		update_sampindex -= m_sample_rate;
 	}
 
+	if (update_sampindex <= m_output_sampindex)
+		return;
+
 	// generate samples to get us up to the appropriate time
 	g_profiler.start(PROFILER_SOUND);
 	assert(m_output_sampindex - m_output_base_sampindex >= 0);