Revert r14497

Log:
	Add missing header #includes.
Policy violation (change not approved by maintainer)
and while discussions where ongoing and no consensus has been reached.

Originally committed as revision 14500 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/swf.h

@@ -25,7 +25,6 @@
 
 #include "libavutil/fifo.h"
 #include "avformat.h"
-#include "avio.h"
 #include "riff.h"    /* for CodecTag */
 
 /* should have a generic way to indicate probable size */