openssl/buffering.rb: call super

* ext/openssl/lib/openssl/buffering.rb (OpenSSL::Buffering#initialize):
  initialize of a module should pass arguments to super.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43774 b2dd03c8-39d4-4d8f-98ff-823fe69b080e