stop yard api doc generation warning.

previously generating api documentation would display
a warning about not being able to resolve a link. solution
was to add some spacing.

test plan:
  * bundle exec rake doc:api;
  * verify that a warning is not displayed re:
    search_controller.rb:40;
  * verify that the search documentation for recipients
    displays as expected.

Change-Id: Ic3654321452f914104fc68e6d9bb9d67955b6b24
Reviewed-on: https://gerrit.instructure.com/17638
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Joe Tanner <joe@instructure.com>
QA-Review: Joel Hough <joel@instructure.com>

app/controllers/search_controller.rb

@@ -83,7 +83,7 @@ class SearchController < ApplicationController
   #   enrollment types for each group to show what they share with this user
   # @response_field permissions[] Only set for contexts. Mapping of requested
   #   permissions that the context grants the current user, e.g.
-  #   {send_messages: true}
+  #   { send_messages: true }
   def recipients
 
     # admins may not be able to see the course listed at the top level (since