optimization: move code for non-zero crc16_align out of the way since it is a rare case
optimization: move code for non-zero crc16_align out of the way since it is a rare case

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