mov: print warning if ff_get_wav_header() fails

Fixes CID717497
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/mov.c

@@ -689,7 +689,9 @@ static int mov_read_wfex(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         return 0;
     st = c->fc->streams[c->fc->nb_streams-1];
 
-    ff_get_wav_header(pb, st->codec, atom.size);
+    if (ff_get_wav_header(pb, st->codec, atom.size) < 0) {
+        av_log(c->fc, AV_LOG_WARNING, "get_wav_header failed\n");
+    }
 
     return 0;
 }