Deploy precheck with alarms in system provides a Blank Error message

[Luis Eduardo Bonatti]

Brief Description
-----------------
Observed that if we do a software deploy precheck when there are alarms in the system then the output displays an Error category without any explanation or info statement i.e., blank error

Severity
--------
Minor

Steps to Reproduce
------------------

Source the openrc file using "source /etc/platform/openrc".
Upload an iso and sig file
Confirm if the state is "available" by executing "software list" command
Execute "fm alarm-list" and confirm there are alarms in the system
Now execute "sudo software --debug deploy precheck <release>" command

Expected Behavior
------------------
Error message should not be left blank. There must be a statement mentioning about the alarms or any other failures in the precheck.

Actual Behavior
----------------
There is a blank Error message in the software deploy precheck <release> command output when there is some system health check failure.

Reproducibility
---------------
Reproducible

System Configuration
--------------------
AIO-SX

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/update/+/911016

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/update/+/911016
Committed: https://opendev.org/starlingx/update/commit/a6c5490d1a13c0938f3d22d977427babe8ac1302
Submitter: "Zuul (22348)"
Branch: master

commit a6c5490d1a13c0938f3d22d977427babe8ac1302
Author: Luis Eduardo Bonatti <email address hidden>
Date: Mon Mar 4 21:10:04 2024 -0300

    Fix deploy precheck returning blank error message

    This commit fix the deploy precheck <release> command output which
    is returning one line with an blank "Error:" when the output is correct.

    Test Plan:
    PASS: Deploy precheck <release> returning without error.
    PASS: Deploy precheck <release> returning expected error.
    PASS: Deploy start failed with expected error.
    PASS: Deploy start

    Note: Exit code 3 was chosen based on exit codes with special meaning
    which the 1 is for catchall general errors and 2 for misuse of shell
    builtins. The number 3 is not allocated with special meaning so it
    was chosen for unhealthy precheck.

    Closes-Bug: 2056106

    Change-Id: Ifed48157f7810eec2881d8a9e011eae8941f3427
    Signed-off-by: Luis Eduardo Bonatti <email address hidden>