* lib/csv.rb:  [DOC] Fix typos

s/occurrs/occurs/, s/interation/iteration/, s/intetionally/intentionally/,
s/modfied/modified/, s/axception/exception/, s/curcuit/circuit/
[ci skip]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43955 b2dd03c8-39d4-4d8f-98ff-823fe69b080e