io.c: update argf lineno
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57124 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
io.c: update argf lineno
ARGF instance. [ruby-core:78728] [Bug #13051]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57124 b2dd03c8-39d4-4d8f-98ff-823fe69b080e