Drop unnecessary intreadwrite.h and bswap.h #includes.

Originally committed as revision 16546 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavutil/internal.h

@@ -96,8 +96,6 @@
 #endif
 
 #include "config.h"
-#include "intreadwrite.h"
-#include "bswap.h"
 
 #ifndef offsetof
 #    define offsetof(T,F) ((unsigned int)((char *)&((T *)0)->F))