Bug#541115: busybox: No longer creates tty[1-4] devices on s390

[Frans Pop <elendil@planet.nl>]

Package: busybox
Severity: serious
Version: 1:1.14.2-1
Tags: d-i

On s390 the installer fails to boot with:
can't open /dev/tty2: No such file or directory
can't open /dev/tty3: No such file or directory
can't open /dev/tty4: No such file or directory

I'm not sure how busybox can be responsible for this, but it's the only 
relevant change in the D-I initrd I can see since my last working test.

The weird thing is that even with busybox 1:1.13.3-1 we only have:
# ls /dev/tty*
/dev/tty       /dev/ttysclp0

But despite that D-I does boot correctly, so I guess the old busybox init 
allowed devices to be referenced in /etc/inittab which do not exist and 
would silently skip them (?).