opttest.rb: adust styles

• sample/optparse/opttest.rb: adjust indent and block stypes. use
  do/end wholly, put spaces around operators, and deep indent in
  parentheses.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42099 b2dd03c8-39d4-4d8f-98ff-823fe69b080e