bug#55856: First LUKS passphrase prompt at Linux boot always fail

[Maxim Cournoyer]

Hello,

It's something I've suffered for a while already on my desktop machine,
but I always assumed I was making a typo or something.

Today I confirmed that without first clearing the input buffer via
multiple backspaces strokes, the first LUKS passphrase (I have many
disks) *always* fail.

Perhaps some boot message or other text gets erroneously redirected to
the standard input and corrupts the user input.

Thanks,

Maxim