rational.c: fix rdoc [ci skip]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57539 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
rational.c: fix rdoc [ci skip]
A patch by Trygve Flathen <at.ruby-lang AT flathen.net> in
[ruby-core:71755]. [Bug #11752]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57539 b2dd03c8-39d4-4d8f-98ff-823fe69b080e