Merge pull request rails#12870 from sauliusg/atom-feed-doc-fix

Fix syntax error in atom_feed example [ci skip]

Author: senny

actionview/lib/action_view/helpers/atom_feed_helper.rb

@@ -64,7 +64,7 @@ module AtomFeedHelper
       #         'xmlns:openSearch' => 'http://a9.com/-/spec/opensearch/1.1/'}) do |feed|
       #       feed.title("My great blog!")
       #       feed.updated((@posts.first.created_at))
-      #       feed.tag!(openSearch:totalResults, 10)
+      #       feed.tag!('openSearch:totalResults', 10)
       #
       #       @posts.each do |post|
       #         feed.entry(post) do |entry|