encoding.c: fix rdoc [ci skip]

* encoding.c (enc_find): [DOC] never accepted a symbol.
  [ruby-dev:48308] [Bug #9966]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46481 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2014-06-21

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46482 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* remove trailing spaces.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46483 b2dd03c8-39d4-4d8f-98ff-823fe69b080e