Revert r14484 hunk that deleted the 'include avcodec.h' statement.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@14495 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/audioconvert.c

@@ -25,6 +25,7 @@
  * @author Michael Niedermayer <michaelni@gmx.at>
  */
 
+#include "avcodec.h"
 #include "audioconvert.h"
 
 typedef struct SampleFmtInfo {