Make sure that values generated for ff_vorbis_len2vlc in

vorbis_parse_setup_hdr_codebooks are in the valid range (<=32).

Originally committed as revision 19373 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/vorbis_dec.c

@@ -292,7 +292,7 @@ static int vorbis_parse_setup_hdr_codebooks(vorbis_context *vc) {
             AV_DEBUG(" ordered, current length: %d \n", current_length);  //FIXME
 
             used_entries=entries;
-            for(;current_entry<used_entries;++current_length) {
+            for(;current_entry<used_entries && current_length <= 32;++current_length) {
                 uint_fast16_t i, number;
 
                 AV_DEBUG(" number bits: %d ", ilog(entries - current_entry));