Remove useless backslash

* lib/optparse.rb (OptionParser::Switch#compsys): remove useless
  backslash which just confuse ruby-mode.el.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66068 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/optparse.rb

@@ -654,7 +654,7 @@ class OptionParser
       return if sopts.empty? and lopts.empty? # completely hidden
 
       (sopts+lopts).each do |opt|
-        # "(-x -c -r)-l[left justify]" \
+        # "(-x -c -r)-l[left justify]"
         if /^--\[no-\](.+)$/ =~ opt
           o = $1
           yield("--#{o}", desc.join(""))