cosmetics: Align muxer/demuxer declarations

Also add missing trailing commas, break long codec_tag lines and
add spaces in codec_tag declarations.

Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/rmenc.c

@@ -471,5 +471,5 @@ AVOutputFormat ff_rm_muxer = {
     .write_header      = rm_write_header,
     .write_packet      = rm_write_packet,
     .write_trailer     = rm_write_trailer,
-    .codec_tag= (const AVCodecTag* const []){ff_rm_codec_tags, 0},
+    .codec_tag         = (const AVCodecTag* const []){ ff_rm_codec_tags, 0 },
 };