Rename an incorrect unreleased entry filename

[koic]

Follow #9167.

This PR adds the following project spec and renames the incorrect unreleased entry filename of #9167.

% bundle exec rspec spec/project_spec.rb:239

Randomized with seed 30085
.F

Failures:

  1) RuboCop Project Changelog future entries For
  /Users/koic/src/github.com/rubocop-hq/rubocop/spec/../changelog/
support_autocorrect_for_style_single_line_block_params.md
  starts with `new_`, `fix_`, or `change_`
     Failure/Error:
  expect(File.basename(path)).to(match(/\A(new|fix|change)_.+/))

       expected
       "support_autocorrect_for_style_single_line_block_params.md" to
       match /\A(new|fix|change)_.+/
       Diff:
       @@ -1 +1 @@
       -/\A(new|fix|change)_.+/
       +"support_autocorrect_for_style_single_line_block_params.md"

     # ./spec/project_spec.rb:240:in `block (6 levels) in
       <top (required)>'

Finished in 0.01424 seconds (files took 1.53 seconds to load)
2 examples, 1 failure

Failed examples:

rspec './spec/project_spec.rb[1:3:4:2:5]' # RuboCop Project Changelog
future entries For
/Users/koic/src/github.com/rubocop-hq/rubocop/spec/../changelog/
support_autocorrect_for_style_single_line_block_params.md
starts with `new_`, `fix_`, or `change_`

---

Before submitting the PR make sure the following are checked:

• The PR relates to only one subject with a clear title and description in grammatically correct, complete sentences.
• Wrote good commit messages.
• Commit message starts with [Fix #issue-number] (if the related issue exists).
• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Ran bundle exec rake default. It executes all tests and runs RuboCop on its own code.
• Added an entry (file) to the changelog folder named {change_type}_{change_description}.md if the new code introduces user-observable changes. See changelog entry format for details.

[bbatsov]

Thanks!