wav: update size check for ds64

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

libavformat/wav.c

@@ -323,7 +323,7 @@ static int wav_read_header(AVFormatContext *s,
         if (avio_rl32(pb) != MKTAG('d', 's', '6', '4'))
             return -1;
         size = avio_rl32(pb);
-        if (size < 16)
+        if (size < 24)
             return -1;
         avio_rl64(pb); /* RIFF size */
         data_size = avio_rl64(pb);