Bug#404894: update-initramfs: zero exit status when initramfs is altered or does not exist

[Tomas Tintera <trosos@seznam.cz>]

Package: initramfs-tools
Version: 0.85e

I think that update-initramfs should return some non-zero error status
when trying to update a non-existing or altered initramfs.

Currently, when I am trying to configure e.g. an uswsusp package
(dpkg-reconfigure uswsusp), and have initramfs removed, the
configuration script calls update-initramfs, which does not update
anything (because of non-existing initramfs) - it only shows the error
message

/boot/initrd.img-2.6.17-2-686 does not exist. Cannot update.

(that is good) and exits with error status 0. The result is that uswsusp
is not properly configured, but dpkg-reconfigure exits with status 0 -
which should not happen, I think (I would expect dpkg-reconfigure to
exit with non-zero error status).

I suggest to use panic() instead of mild_panic() in altered_check() in
the update-initramfs script.