[title]
Verify that the bootmap file is up-to-date

[description]
With a backlevel bootmap file, you might no longer be able to boot your Linux
instance.

This check compares the file metadata to verify that none of the boot data
that is referenced by the bootmap file has been modified after the bootmap
file was created. The boot data typically includes, a kernel image, initial
RAM disk (initrd), and a kernel parameter file.

A backlevel bootmap file can be the result of upgrading the kernel with a new
kernel image without running "zipl" to update the bootmap file accordingly.

This check applies only if the following assumptions are all true:
- The boot device is a disk device.
- The bootmap file has been created from specifications in the "zipl"
  configuration file, /etc/zipl.conf.
- /etc/zipl.conf describes a single boot configuration that can but need not
  provide a boot menu.

Distributions tools typically use "zipl" according to these assumptions when
creating a boot disk.
