mlpdec: dont leave a invalid huff_lsb in the context.

Fix assertion failure

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/mlpdec.c

@@ -720,6 +720,7 @@ static int read_channel_params(MLPDecodeContext *m, unsigned int substr,
 
     if (cp->huff_lsbs > 24) {
         av_log(m->avctx, AV_LOG_ERROR, "Invalid huff_lsbs.\n");
+        cp->huff_lsbs = 0;
         return AVERROR_INVALIDDATA;
     }