ffmetaenc: Use correct format specifiers.

Use printf format macros from inttypes.h.
Additionally, this fixes a warning when building with clang.

libavformat/ffmetaenc.c

@@ -19,6 +19,8 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <inttypes.h>
+
 #include "avformat.h"
 #include "ffmeta.h"
 
@@ -72,8 +74,8 @@ static int write_trailer(AVFormatContext *s)
         put_tag(s->pb, ID_CHAPTER);
         put_byte(s->pb, '\n');
         url_fprintf(s->pb, "TIMEBASE=%d/%d\n", ch->time_base.num, ch->time_base.den);
-        url_fprintf(s->pb, "START=%lld\n", ch->start);
-        url_fprintf(s->pb, "END=%lld\n",   ch->end);
+        url_fprintf(s->pb, "START=%"PRId64"\n", ch->start);
+        url_fprintf(s->pb, "END=%"PRId64"\n",   ch->end);
         write_tags(s->pb, ch->metadata);
     }