libav-bitrate.c: fix header

[Nikoli]

$ head libav-bitrate.c -n16
// libav2yuv
// adapted from
// avcodec_sample.0.4.9.cpp

// A small sample program that shows how to use libavformat and libavcodec to
// read video from a file.
//
// This version is for the 0.4.9-pre1 release of ffmpeg. This release adds the
// av_read_frame() API call, which simplifies the reading of video frames 
// considerably. 
//
//gcc -O3 -I/usr/local/include/ffmpeg -I/usr/local/include/mjpegtools -lavcodec -lavformat -lavutil -lmjpegutils libav2yuv.c -o libav2yuv
//

//#include <yuv4mpeg.h>
//#include <mpegconsts.h>

Please update comments.

[silicontrip]

cleaned up.