avformat/mpl2dec: Avoid variable that is always zero

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

libavformat/mpl2dec.c

@@ -83,7 +83,6 @@ static int mpl2_read_header(AVFormatContext *s)
 {
     MPL2Context *mpl2 = s->priv_data;
     AVStream *st = avformat_new_stream(s, NULL);
-    int res = 0;
 
     if (!st)
         return AVERROR(ENOMEM);
@@ -122,7 +121,7 @@ static int mpl2_read_header(AVFormatContext *s)
     }
 
     ff_subtitles_queue_finalize(s, &mpl2->q);
-    return res;
+    return 0;
 }
 
 static int mpl2_read_packet(AVFormatContext *s, AVPacket *pkt)