avformat/matroskaenc: Reindent after previous commit

Also remove { } after an if if there is only one statement inside { }.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

libavformat/matroskaenc.c

@@ -1297,9 +1297,8 @@ static int mkv_write_track(AVFormatContext *s, MatroskaMuxContext *mkv,
 
             put_ebml_uint(pb, MATROSKA_ID_CODECDELAY, codecdelay);
         }
-    if (par->codec_id == AV_CODEC_ID_OPUS) {
+        if (par->codec_id == AV_CODEC_ID_OPUS)
             put_ebml_uint(pb, MATROSKA_ID_SEEKPREROLL, OPUS_SEEK_PREROLL);
-    }
 
         put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);