avformat/mov: Fix extradata memleak

Fixes: crbug 822705

Reported-by: Matt Wolenetz <wolenetz@google.com>
Reviewed-by: Matt Wolenetz <wolenetz@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 0a8133119c)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/mov.c

@@ -2391,6 +2391,12 @@ static int mov_read_stsd(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 
     return mov_finalize_stsd_codec(c, pb, st, sc);
 fail:
+    if (sc->extradata) {
+        int j;
+        for (j = 0; j < sc->stsd_count; j++)
+            av_freep(&sc->extradata[j]);
+    }
+
     av_freep(&sc->extradata);
     av_freep(&sc->extradata_size);
     return ret;