avformat/mpjpeg: Remove mpjpeg_write_trailer

It does nothing.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/mpjpeg.c

@@ -49,11 +49,6 @@ static int mpjpeg_write_packet(AVFormatContext *s, AVPacket *pkt)
     return 0;
 }
 
-static int mpjpeg_write_trailer(AVFormatContext *s)
-{
-    return 0;
-}
-
 static const AVOption options[] = {
     { "boundary_tag",    "Boundary tag", offsetof(MPJPEGContext, boundary_tag),   AV_OPT_TYPE_STRING, {.str = BOUNDARY_TAG}, .flags = AV_OPT_FLAG_ENCODING_PARAM },
     { NULL },
@@ -76,7 +71,6 @@ AVOutputFormat ff_mpjpeg_muxer = {
     .video_codec       = AV_CODEC_ID_MJPEG,
     .write_header      = mpjpeg_write_header,
     .write_packet      = mpjpeg_write_packet,
-    .write_trailer     = mpjpeg_write_trailer,
     .flags             = AVFMT_NOTIMESTAMPS,
     .priv_class        = &mpjpeg_muxer_class,
 };