Fix NoMethodError [ci skip]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58547 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

sample/cbreak.rb

@@ -30,7 +30,7 @@ end
 cbreak();
 
 print("this is no-echo line: ");
-readline().print
+readline().display
 cooked();
 print("this is echo line: ");
 readline()