warn_reboot kernel install option

[Andy Whitcroft]

We have a report that the warn_reboot kernel install option does not
work.  This option is a debian packaging variable used in the
debian/control-scripts/*.  The nominal meaning of this is documented
as below.

  my $warn_reboot     = 'Yes';     # Warn that we are installing a version of
                                   # the kernel we are running

In reality this variable has no effect on our notification mechanism
at all, we always report the installation and request a reboot
unconditionally:

    # Warn of a reboot
    if (-x $notifier) {
      system($notifier);
    }

The reporter wishes this variable to have a more direct meaning, of
preventing all reboot warnings when set.  Their use case is for
people using ksplice to install fixes from the newer kernel without
rebooting, and thus are never interested in rebooting.

Cirtainly I can see that there is a use case, for suppressing any
notificiation.  The real question is whether we can reuse this existing
variable to do this or would need a new one.  It should be noted that
this appears to have never been implemented and therefore changing its
meaning would be low risk.

Thoughts?

-apw