csv.rb: fix field_size_limit check
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57406 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
csv.rb: fix field_size_limit check
column since r55985. [ruby-dev:49964] [Bug #13149]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57406 b2dd03c8-39d4-4d8f-98ff-823fe69b080e