Zelda HLE: Only alert for mixing into back buffers for recent UCode v…

…ersions.

On older versions there is no such concept of a "back buffer" since positional
audio is not supported. These buffers are just used for temp mixing, and while
it would be really nice if we could support more of that inter-buffer mixing
(TODO :) ) it does not warrant a PanicAlert at this time.

Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp

@@ -808,7 +808,7 @@ void ZeldaAudioRenderer::PrepareFrame()
 	// TODO: Back left and back right should have a filter applied to them,
 	// then get mixed into front left and front right. In practice, TWW never
 	// uses this AFAICT. PanicAlert to help me find places that use this.
-	if (m_buf_back_left[0] != 0 || m_buf_back_right[0] != 0)
+	if (!(m_flags & LIGHT_PROTOCOL) && (m_buf_back_left[0] != 0 || m_buf_back_right[0] != 0))
 		PanicAlert("Zelda HLE using back mixing buffers");
 
 	// Add reverb data from previous frame.