https://bugzilla.redhat.com/show_bug.cgi?id=515589
It ends up installing the label.so control plugin which isn't supposed
to get installed into the initrd. this makes cairo and libX11 and all sorts of
things move into the initrd that aren't supposed to.
The reason this works is that inst will refuse to overwrite a file that
already exists. We jsut make plymouth's code to ask for a password have the
same name as 90crypt's password asking script, and it will override 90crypt's
script while leaving everything else intact.