Bug#819288: console-setup-linux: keyboard-setup.sh init script (actually, the cached scripts) rely on /tmp, which may not be mounted at early boot

[Anthony DeRobertis <aderobertis@metrics.net>]

Package: console-setup
Version: 1.152
Followup-For: Bug #819288

Upgrading from 1.147 to 1.152 has made this change, as recorded by
etckeeper:

diff --git a/console-setup/cached_setup_keyboard.sh b/console-setup/cached_setup_keyboard.sh
index 30b46c1..ad6d653 100755
--- a/console-setup/cached_setup_keyboard.sh
+++ b/console-setup/cached_setup_keyboard.sh
@@ -10,4 +10,4 @@ kbd_mode '-u' < '/dev/tty3'
 kbd_mode '-u' < '/dev/tty4' 
 kbd_mode '-u' < '/dev/tty5' 
 kbd_mode '-u' < '/dev/tty6' 
-loadkeys '/etc/console-setup/cached_UTF-8_del.kmap.gz' > '/dev/null' 
+loadkeys '/tmp/tmpkbd.ckGFQb' > '/dev/null' 

That is... almost certainly wrong.

Running "setupcon --save-only" fixed it. But,
"dpkg-reconfigure console-setup" breaks it again. (Both of these are
repeatable)

(It also added a : to both cached_setup_terminal.sh and
cached_setup_font.sh, but maybe that's intended for some reason [it
appears harmless enough]).

-- System Information:
Debian Release: stretch/sid
  APT prefers testing-debug
  APT policy: (500, 'testing-debug'), (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 4.7.0-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages console-setup depends on:
ii  console-setup-linux     1.152
ii  debconf                 1.5.59
ii  keyboard-configuration  1.152
ii  xkb-data                2.18-1

console-setup recommends no packages.

Versions of packages console-setup suggests:
ii  locales   2.24-5
ii  lsb-base  9.20161016

Versions of packages keyboard-configuration depends on:
ii  debconf                 1.5.59
ii  liblocale-gettext-perl  1.07-3+b1

Versions of packages console-setup-linux depends on:
ii  init-system-helpers     1.45
ii  initscripts             2.88dsf-59.8
ii  kbd                     2.0.3-2
ii  keyboard-configuration  1.152

console-setup-linux suggests no packages.

Versions of packages console-setup is related to:
pn  console-common        <none>
pn  console-data          <none>
pn  console-tools         <none>
pn  gnome-control-center  <none>
ii  kbd                   2.0.3-2
ii  systemd               231-9

-- debconf information:
  console-setup/use_system_font:
* keyboard-configuration/altgr: The default for the keyboard layout
* keyboard-configuration/switch: No temporary switch
* keyboard-configuration/compose: No compose key
* keyboard-configuration/layoutcode: us
* console-setup/fontface47: TerminusBold
* keyboard-configuration/variantcode:
* keyboard-configuration/model: Generic 105-key (Intl) PC
* console-setup/codeset47: # Latin1 and Latin5 - western Europe and Turkic languages
* keyboard-configuration/layout:
* keyboard-configuration/modelcode: pc105
  console-setup/guess_font:
  keyboard-configuration/unsupported_layout: true
  console-setup/codesetcode: Lat15
* keyboard-configuration/variant: English (US)
* keyboard-configuration/xkb-keymap: us
  debian-installer/console-setup-udeb/title:
* keyboard-configuration/optionscode:
  keyboard-configuration/ctrl_alt_bksp: false
  console-setup/fontsize-text47: 8x16
  keyboard-configuration/unsupported_options: true
* console-setup/charmap47: UTF-8
  keyboard-configuration/unsupported_config_layout: true
* keyboard-configuration/toggle: No toggling
  console-setup/framebuffer_only:
  keyboard-configuration/unsupported_config_options: true
* keyboard-configuration/other:
* keyboard-configuration/store_defaults_in_debconf_db: true
  console-setup/store_defaults_in_debconf_db: true
  console-setup/fontsize: 8x16
* console-setup/fontsize-fb47: 8x16