output/{alsa,osx}: remove comment after PcmExport::Export()

src/output/plugins/AlsaOutputPlugin.cxx

@@ -873,12 +873,6 @@ AlsaOutput::Play(const void *chunk, size_t size)
 
 	const auto e = pcm_export->Export({chunk, size});
 	if (e.size == 0)
-		/* the DoP (DSD over PCM) filter converts two frames
-		   at a time and ignores the last odd frame; if there
-		   was only one frame (e.g. the last frame in the
-		   file), the result is empty; to avoid an endless
-		   loop, bail out here, and pretend the one frame has
-		   been played */
 		return size;
 
 	std::unique_lock<Mutex> lock(mutex);

src/output/plugins/OSXOutputPlugin.cxx

@@ -887,12 +887,6 @@ OSXOutput::Play(const void *chunk, size_t size)
 #ifdef ENABLE_DSD
         if (dop_enabled) {
 		const auto e = pcm_export->Export({chunk, size});
-		/* the DoP (DSD over PCM) filter converts two frames
-		   at a time and ignores the last odd frame; if there
-		   was only one frame (e.g. the last frame in the
-		   file), the result is empty; to avoid an endless
-		   loop, bail out here, and pretend the one frame has
-		   been played */
 		if (e.size == 0)
 			return size;