Clear residues only in not coded channel. This fixes overwriting coded residues with zeros if first channel is coded and second is not.

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

libavcodec/wmalosslessdec.c

@@ -960,7 +960,7 @@ static int decode_subframe(WmallDecodeCtx *s)
                     use_normal_update_speed(s, i);
                 revert_cdlms(s, i, 0, subframe_len);
             } else
-                memset(s->channel_residues, 0, sizeof(s->channel_residues));
+                memset(s->channel_residues[i], 0, sizeof(s->channel_residues[i]));
     }
     if (s->do_mclms)
         revert_mclms(s, subframe_len);