MegaLinter reports 1 error found even when yamlint reports multiple errors

[james-garriss]

Describe the bug

When MegaLinter runs yamllint, and yamllint reports multiple errors, MegaLinter reports that there was only 1 error.

To Reproduce

1. Use MegaLinter to lint the MegaLinter YAML file and the yamlint YAML file.
2. Add a few linting issues, like extra blank lines.
3. Setup a MegaLinter config file that only runs yamllint.

ENABLE_LINTERS:
  - YAML_YAMLLINT

4. Run MegaLinter.
5. See that MegaLinter reports that there is only 1 error, but yamllint actually finds multiple errors.

Note: This appears to be the same error that someone else previously reported about Bandit.

Expected behavior

I would expect MegaLinter to report the sum total number of errors that yamllint finds.

Screenshots

❌ Linted [YAML] files with [yamllint]: Found 1 error(s) - (0.21s)
- Using [yamllint v1.33.0] https://megalinter.io/7.6.0/descriptors/yaml_yamllint
- MegaLinter key: [YAML_YAMLLINT]
- Rules config: [/.yamllint.yml]
- Number of files analyzed: [4]
--Error detail:
.mega-linter.yml
  6:1       error    too many blank lines (1 > 0)  (empty-lines)

megalinter.yml
  17:1      error    trailing spaces  (trailing-spaces)
  63:21     error    no new line character at the end of file  (new-line-at-end-of-file)

yamllint.yml
  35:19     error    no new line character at the end of file  (new-line-at-end-of-file)

[nvuillam]

@james-garriss good catch, thanks for reporting, PR is on the way :)