Remove 'currently unused' warning about SAMPLE_FMT_xxx.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@15046 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/avcodec.h

@@ -341,7 +341,6 @@ enum CodecType {
 };
 
 /**
- * Currently unused, may be used if 24/32 bits samples are ever supported.
  * all in native-endian format
  */
 enum SampleFormat {