Bug in /etc/update-motd.d/50-landscape-sysinfo script - incorrect variable used for load threshold calculation

[Markus]

[ Impact ]

 * The CPU load is incorrectly calculated, and users won't get system info in
the message-of-the-day (motd).

 * The `cores` variable was misnamed; it should be `CORES` since bash variables are case-sensitive

* Affects landscape-client on noble, mantic, jammy, and focal.

[ Test Plan ]

Steps to Reproduce:

    1. Open the /etc/update-motd.d/50-landscape-sysinfo script.
    2. Notice the line where THRESHOLD is set: THRESHOLD="${cores:-1}.0".
    3. The correct variable should be CORES instead of cores.

To trigger MOTD and view incorrect calculation:

sudo run-parts /etc/update-motd.d/
Notice message: " System information disabled due to load higher than 1.0" even on systems with multiple cores.

[ Where problems could occur ]

 * This fix will necessarily run the system process info on more systems during MOTD. If the CPU load threshold was poorly chosen, then overly-loaded systems might be slow during MOTD while landscape-sysinfo runs

[Spencer Runde (spencerrunde)]

Hi Markus,

Thank you for your bug report. We have an SRU in progress for this, and it should land shortly.

[Spencer Runde (spencerrunde)]

Original bug report:

===

There is a bug in the /etc/update-motd.d/50-landscape-sysinfo (Symlink to /usr/share/landscape/landscape-sysinfo.wrapper) script in Ubuntu. The script incorrectly sets the load threshold due to a typo, causing the system information to be disabled unnecessarily when the system load is actually within acceptable limits.

Steps to Reproduce:

    1. Open the /etc/update-motd.d/50-landscape-sysinfo script.
    2. Notice the line where THRESHOLD is set: THRESHOLD="${cores:-1}.0".
    3. The correct variable should be CORES instead of cores.

Expected Behavior:
The threshold should be calculated based on the number of CPU cores, e.g., THRESHOLD="${CORES:-1}.0", and system information should be displayed correctly when the load is below this threshold.

Actual Behavior:
The threshold is incorrectly set to 1.0 due to the typo, causing system information to be disabled unnecessarily.

Version Information:

    Ubuntu 24.04 LTS: landscape-common 24.02-0ubuntu5
    Ubuntu 22.04.4 LTS: landscape-common 23.02-0ubuntu1~22.04.2