Description of problem:
When upgrading a 6.12 to 6.13 with insufficient system resources, the "check-tuning-requirements" check rightfully raises an error and can't be skipped (the upgrade would fail).

However, the resulting foreman maintain output is missleading when there is also a skipped check in the mix:

1. foreman-maintain upgrade check --target-version 6.13 --whitelist="repositories-validate"
   …
   --------------------------------------------------------------------------------
   Check if system requirements match current tuning profile: [FAIL]

ERROR: The installer is configured to use the default tuning profile and does not meet the requirements.
The number of CPU cores for the system is 2 but the currently configured tuning profile requires 4.
The system memory is 7 GB but the currently configured tuning profile requires 20 GB.

--------------------------------------------------------------------------------
…
--------------------------------------------------------------------------------
Validate availability of repositories: [SKIPPED]
--------------------------------------------------------------------------------
Scenario [Checks before upgrading to Satellite 6.13] failed.

The following steps ended up in failing state:

[check-tuning-requirements]

Resolve the failed steps and rerun the command.

If the situation persists and, you are unclear what to do next,
contact Red Hat Technical Support.

In case the failures are false positives, use
--whitelist="repositories-validate"

The output suggests that running with `--whitelist="repositories-validate"` would help, but it does not as that step is skipped already and not the culprit of the issue.

Version-Release number of selected component (if applicable):
foreman maintain 1.2.6

How reproducible:
100%

Steps to Reproduce:
1. install a 6.12 with --disable-system-checks
2. have one of the skippable checks fail (like repository validate)
3. foreman-maintain upgrade check --target-version 6.13 --whitelist="repositories-validate"

Actual results:
see above, it suggests to run it again, which wouldn't help

Expected results:
don't add the "false positives" part of the message if the only skippable checks are already skipped

Additional info: