avformat/omadec: Don't output uninitialized values

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavformat/omadec.c

@@ -491,7 +491,7 @@ static int oma_read_header(AVFormatContext *s)
         AV_WL16(&edata[6],  jsflag);        // coding mode
         AV_WL16(&edata[8],  jsflag);        // coding mode
         AV_WL16(&edata[10], 1);             // always 1
-        // AV_WL16(&edata[12], 0);          // always 0
+        AV_WL16(&edata[12], 0);             // always 0
 
         avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
         break;