Fix an incorrect auto-correct for Style/RedundantParentheses

[koic]

This PR fixes an incorrect auto-correct for Style/RedundantParentheses when enclosed in parentheses at while-post or until-post.

The following is a reproduction step.

% rubocop example1.rb --only Style/RedundantParentheses -a
Inspecting 1 file
E

Offenses:

example1.rb:3:5: E: Lint/Syntax: unexpected token tIDENTIFIER
(Using Ruby 2.2 parser; configure using TargetRubyVersion parameter,
under AllCops)
end whilefoo
    ^^^^^^^^
example1.rb:3:10: C: [Corrected] Style/RedundantParentheses:
Don't use parentheses around a method call.
end while(foo)
    ^^^^^

1 file inspected, 2 offenses detected, 1 offense corrected

This is a broken while.

% git diff
diff --git a/example1.rb b/example1.rb
index cf5523f..5f47ae4 100644
--- a/example1.rb
+++ b/example1.rb
@@ -1,3 +1,3 @@
 begin
   do_something
-end while(foo)
+end whilefoo

This will not be warned when while ... end.

% cat example2.rb
while(foo)
  do_something
end

% rubocop example2.rb --only Style/RedundantParentheses
Inspecting 1 file
.

1 file inspected, no offenses detected

So this PR changes to the same behavior.

---

Before submitting the PR make sure the following are checked:

• 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.
• Added an entry to the Changelog if the new code introduces user-observable changes. See changelog entry format.
• The PR relates to only one subject with a clear title
  and description in grammatically correct, complete sentences.
• Run bundle exec rake default. It executes all tests and RuboCop for itself, and generates the documentation.

[bbatsov]

👍