avfilter/ccfifo: Improve included headers

We don't need to include fifo.h, because we don't need AVFifo
as a complete type. Also add the other used headers directly.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavfilter/ccfifo.c

@@ -22,6 +22,7 @@
  */
 
 #include "ccfifo.h"
+#include "libavutil/fifo.h"
 
 #define MAX_CC_ELEMENTS 128
 

libavfilter/ccfifo.h

@@ -29,15 +29,17 @@
 #ifndef AVFILTER_CCFIFO_H
 #define AVFILTER_CCFIFO_H
 
-#include "libavutil/avutil.h"
+#include <stddef.h>
+#include <stdint.h>
+
 #include "libavutil/frame.h"
-#include "libavutil/fifo.h"
+#include "libavutil/rational.h"
 
 #define CC_BYTES_PER_ENTRY 3
 
 typedef struct CCFifo {
-    AVFifo *cc_608_fifo;
-    AVFifo *cc_708_fifo;
+    struct AVFifo *cc_608_fifo;
+    struct AVFifo *cc_708_fifo;
     AVRational framerate;
     int expected_cc_count;
     int expected_608;