10l found by valgrind

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@6099 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/mpegaudiodec.c

@@ -1745,6 +1745,7 @@ static int huffman_decode(MPADecodeContext *s, GranuleDef *g,
                 if (get_bits1(&s->gb))
                     v = -v;
                 g->sb_hybrid[s_index+!!y] = v;
+                g->sb_hybrid[s_index+ !y] = 0;
             }
             s_index+=2;
         }