Add comment to kickstart stating how LAT hook syntax errors are rendered

[Eric MacDonald]

Brief Description
-----------------
The Linux Assembly Tool parses a kickstart file containing various hook segments that are syntactically delineated with statements that start with '%'. The example below shows the start and end syntax of a hook block.

%post --interpreter=/bin/bash

<kickstart bash code goes here>

%end

If LAT detects a hook block syntax error it fails the install and renders it as a Permission error.

This Jira calls for 2 kickstart comments to be added saying
1. How hook syntax errors are rendered with a permission error.
2. the kickstart must end with a Line Feed after the last %end directive

Severity
--------
Minor: code comment only

Steps to Reproduce
------------------
Install a system after removing the LF from the end of the file.

Expected Behavior
------------------
install succeeds

Actual Behavior
----------------
install fails

Reproducibility
---------------
100% reproducible

System Configuration
--------------------
Any

Branch/Pull Time/Commit
-----------------------
N/A issue does not exist in master branch. Just need comments added to code.

Last Pass
---------
N/A

Timestamp/Logs
--------------
Run post install nochroot script /tmp/lat/lat_post_nochroot_script/10_script
+ IMAGE_ROOTFS=/sysroot/ostree/1
+ /tmp/lat/lat_post_nochroot_script/10_script
./lat-installer.sh: line 539: /tmp/lat/lat_post_nochroot_script/10_script: Permission denied
Run Kickstart Post Install Script failed in /sysroot/ostree/1

[ 349.536291] sysrq: Resetting

Test Activity
-------------
N/A

Workaround
----------
N/A

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/metal/+/922027

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/metal/+/922027
Committed: https://opendev.org/starlingx/metal/commit/f0da76d820b1892a8cab01dc4ab897ab7c3f7694
Submitter: "Zuul (22348)"
Branch: master

commit f0da76d820b1892a8cab01dc4ab897ab7c3f7694
Author: Eric MacDonald <email address hidden>
Date: Fri Jun 14 11:20:44 2024 -0400

    Add LAT hook segment syntax error rendering code comment to kickstarts

    The Linux Assembly Tool parses a kickstart file containing various
    hook segments that are syntactically delineated with statements that
    start with '%'.

    The example below shows the start and end syntax of a hook block.

    %post --interpreter=/bin/bash

    <kickstart bash code goes here>

    %end

    If LAT detects a hook block syntax error it fails the install and
    renders it as a Permission denied like this:

    ./lat-installer.sh: line 539:
    /tmp/lat/lat_post_nochroot_script/10_script: Permission denied

    This update adds a comment to the kickstart file header explaining
    how LAT renders hook syntax errors as file permission denied and
    a comment at the end of the kickstart warning not to remove the
    Line Feed at the end of the kickstart files.

    Test Plan:

    PASS: Verify spelling and format of added code comments.
    PASS: Verify kickstart.cfg has a Line Feed at the end of the last
          kickstart.cfg and miniboot.cfg files. They were already there.

    Closes-Bug: 2069432
    Change-Id: Ic4cd168e784abdba98e45e1837749915db9c4e43
    Signed-off-by: Eric MacDonald <email address hidden>