Fix incorrect comment

webrtc/modules/audio_coding/codecs/audio_encoder.h

Index: webrtc/modules/audio_coding/codecs/audio_encoder.h
diff --git a/webrtc/modules/audio_coding/codecs/audio_encoder.h b/webrtc/modules/audio_coding/codecs/audio_encoder.h
index 553c35e2690f76b29431f86063bd2dc39e1ca07f..ebb5d36bfd5c1b8f55d8d07d1e618e4c33c84754 100644
--- a/webrtc/modules/audio_coding/codecs/audio_encoder.h
+++ b/webrtc/modules/audio_coding/codecs/audio_encoder.h
@@ -125,7 +125,7 @@ class AudioEncoder {
   // Tells the encoder about the highest sample rate the decoder is expected to
   // use when decoding the bitstream. The encoder would typically use this
   // information to adjust the quality of the encoding. The default
-  // implementation just returns true.
+  // implementation does nothing.
   virtual void SetMaxPlaybackRate(int frequency_hz);
 
   // Tells the encoder what the projected packet loss rate is. The rate is in