ffmetaenc: remove useless initializers

Originally committed as revision 26114 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/ffmetaenc.c

@@ -91,8 +91,6 @@ AVOutputFormat ffmetadata_muxer = {
     .name          = "ffmetadata",
     .long_name     = NULL_IF_CONFIG_SMALL("FFmpeg metadata in text format"),
     .extensions    = "ffmeta",
-    .video_codec   = CODEC_ID_NONE,
-    .audio_codec   = CODEC_ID_NONE,
     .write_header  = write_header,
     .write_packet  = write_packet,
     .write_trailer = write_trailer,