fftools/ffprobe: Remove redundant check before avcodec_free_context()

Besides being unnecessary it is also safer: If the error for an
unrecognized option were triggered (which seems to be impossible right
now), it might be that the stream whose codecpar is accessed is NULL.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

fftools/ffprobe.c

@@ -3078,8 +3078,7 @@ static void close_input_file(InputFile *ifile)
 
     /* close decoder for each stream */
     for (i = 0; i < ifile->nb_streams; i++)
-        if (ifile->streams[i].st->codecpar->codec_id != AV_CODEC_ID_NONE)
-            avcodec_free_context(&ifile->streams[i].dec_ctx);
+        avcodec_free_context(&ifile->streams[i].dec_ctx);
 
     av_freep(&ifile->streams);
     ifile->nb_streams = 0;