PPM filename check-digit calculation may not be correct

[jaames]

flipnote.js/src/parsers/filename/ppm.ts

Line 36 in 083ca4e

export const ppmFilenameCalculateCheckDigit = (filename: string) => {

Seems to work on some samples, but not on others. Wonder if it uses the current console MAC suffix, and not the one from the original filename?