avformat/dss: Remove superfluous headers

Both attributes.h and bswap.h have been included from the very beginning
of this muxer without there being any reason to do so.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/dss.c

@@ -19,8 +19,6 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#include "libavutil/attributes.h"
-#include "libavutil/bswap.h"
 #include "libavutil/channel_layout.h"
 #include "libavutil/intreadwrite.h"