ChangeLog: remove conflict mark

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48143 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
parse.y: Ripper.sexp returns error

* ext/ripper/lib/ripper/sexp.rb (Ripper.sexp, Ripper.sexp_raw):
  return nil on error.  [ruby-dev:48678] [Bug #10405]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48144 b2dd03c8-39d4-4d8f-98ff-823fe69b080e