Ruby

• transcode.c (make_econv_exception): rename instance variable names
  for storing encoding names.
  (ecerr_source_encoding_name): method renamed.
  (ecerr_destination_encoding_name): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@18987 b2dd03c8-39d4-4d8f-98ff-823fe69b080e