Fix linking: emms_c is a macro, #include the correct header file.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9238 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavformat/grab.c

@@ -19,6 +19,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 #include "avformat.h"
+#include "dsputil.h"
 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/ioctl.h>