minor wording change for -M in the usage
minor wording change for -M in the usage

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