avcodec/h261dec: Don't use too big max_depth in get_vlc2()

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

libavcodec/h261dec.c

@@ -431,7 +431,7 @@ static int h261_decode_mb(H261Context *h)
 
     // Read cbp
     if (HAS_CBP(h->mtype))
-        cbp = get_vlc2(&s->gb, h261_cbp_vlc.table, H261_CBP_VLC_BITS, 2) + 1;
+        cbp = get_vlc2(&s->gb, h261_cbp_vlc.table, H261_CBP_VLC_BITS, 1) + 1;
 
     if (s->mb_intra) {
         s->current_picture.mb_type[xy] = MB_TYPE_INTRA;