fix bug in the blocksize field of the subframe header spec
fix bug in the blocksize field of the subframe header spec

fredericgermain/flac,Distrotech/flac,kode54/flac,Distrotech/flac,LordJZ/libflac,Distrotech/flac,kode54/flac,Distrotech/flac,waitman/flac,waitman/flac,waitman/flac,LordJZ/libflac,waitman/flac,LordJZ/libflac,LordJZ/libflac,fredericgermain/flac,fredericgermain/flac,fredericgermain/flac,kode54/flac,waitman/flac,kode54/flac