Fix example action dispatch in mime type

actionpack/lib/action_dispatch/http/mime_type.rb

@@ -38,7 +38,7 @@ def self.[](type)
   #       respond_to do |format|
   #         format.html
   #         format.ics { render :text => post.to_ics, :mime_type => Mime::Type["text/calendar"]  }
-  #         format.xml { render :xml => @people.to_xml }
+  #         format.xml { render :xml => @people }
   #       end
   #     end
   #   end