Fix an incorrect auto-correct for Lint/AmbiguousOperator

[koic]

This PR fixes the following incorrect auto-correct for Style/MethodCallWithArgsParentheses with Lint/AmbiguousOperator.

% cat example.rb
def foo(&block)
  do_something &block
end

% rubocop --only Style/MethodCallWithArgsParentheses,Lint/AmbiguousOperator -a
Inspecting 4 files
..WC

Offenses:

example.rb:2:3: C: [Corrected] Style/MethodCallWithArgsParentheses: Use
parentheses for method calls with arguments.
  do_something &block
  ^^^^^^^^^^^^^^^^^^^
example.rb:2:16: W: [Corrected] Lint/AmbiguousOperator: Ambiguous block
operator. Parenthesize the method arguments if it's surely a block
operator, or add a whitespace to the right of the & if it should be a
binary AND.
  do_something &block
               ^
ripper/example.rb:6:5: C: [Corrected]
Style/MethodCallWithArgsParentheses: Use parentheses for method calls
with arguments.
    raise message
    ^^^^^^^^^^^^^

4 files inspected, 3 offenses detected, 3 offenses corrected

Before

Syntax error with redundant closing parentheses.

% cat example.rb
def foo(&block)
  do_something(&block))
end

% ruby -c example.rb
example.rb:2: syntax error, unexpected ')', expecting end
  do_something(&block))

After

Valid syntax.

% cat example.rb
def foo(&block)
  do_something(&block)
end

---

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• 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).
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• 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.