Bug#597582: initramfs-tools should not ignore failing hook scripts

[Ian Jackson <ijackson@chiark.greenend.org.uk>]

Package: initramfs-tools
Version: 0.92o
Severity: important

If an initramfs hook script exits with a nonzero exit status,
update-initramfs carries on anyway!

To reproduce: 

1. create /etc/initramfs-tools/hooks/broken containing
  #!/bin/sh -e
  broken!

2. run update-initramfs in a way that makes it do some work.

3. Observe:
  /etc/initramfs-tools/hooks/broken: line 2: broken!: command not found
but the initramfs is still created and installed.

This kind of thing is liable to make systems unbootable, surely.

Ian.