avformat/utils: Remove superfluous headers

stdarg.h has been included in 780d7897a9
for ff_url_join(). This header became unnecessary when this function was
moved into a separate file in df9f22d42b.

libavutil/pixdesc.h has been included for av_get_pix_fmt_name() in
603b8bc2a1 and is unused since commit
2fb7501938 that removed the stuff belonging
to FF_API_FORMAT_PARAMETERS. Notice that this file still uses
AV_PIX_FMT_NONE and that therefore the header libavutil/pixfmt.h has
been included (this header is included in pixdesc.h as well as also in
libavutil/internal.h which is also included).

libavutil/time_internal.h has been included for gmtime_r() in commit
e7dd97b5d8cd6ea150446591f37a5946e8ab7cfb; it is unused since commit
b72a7b96f8 which basically moved the code
making use of gmtime_r() to libavutil/dict.c to use in
avpriv_dict_set_timestamp().

audiointerleave.h has been added in c26e58e32c
because of ff_interleave_compare_dts() (at that time the muxing code
was not split from utils.c yet); said function became static in commit
101e1f6ff9, making this header redundant.

metadata.h has been mostly included for what now resides in
libavutil/dict.h. The stuff that now resides in metadata.h has only been
used briefly: From commits ed7694d8cf to
d60a9f52eb.

riff.h has been added in 45da8124a0
because riff.h once contained declarations for (ff_)codec_get_tag().
This was changed in bfe5454cd2.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

libavformat/utils.c

@@ -19,7 +19,6 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#include <stdarg.h>
 #include <stdint.h>
 
 #include "config.h"
@@ -31,26 +30,22 @@
 #include "libavutil/mathematics.h"
 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"
-#include "libavutil/pixdesc.h"
+#include "libavutil/pixfmt.h"
 #include "libavutil/thread.h"
 #include "libavutil/time.h"
-#include "libavutil/time_internal.h"
 #include "libavutil/timestamp.h"
 
 #include "libavcodec/bytestream.h"
 #include "libavcodec/internal.h"
 #include "libavcodec/raw.h"
 
-#include "audiointerleave.h"
 #include "avformat.h"
 #include "avio_internal.h"
 #include "id3v2.h"
 #include "internal.h"
-#include "metadata.h"
 #if CONFIG_NETWORK
 #include "network.h"
 #endif
-#include "riff.h"
 #include "url.h"
 
 #include "libavutil/ffversion.h"