Fix creation example in nested attributes.

activerecord/lib/active_record/nested_attributes.rb

@@ -46,7 +46,7 @@ module NestedAttributes #:nodoc:
     # create the member and avatar in one go:
     #
     #   params = { :member => { :name => 'Jack', :avatar_attributes => { :icon => 'smiling' } } }
-    #   member = Member.create(params)
+    #   member = Member.create(params['member'])
     #   member.avatar.id # => 2
     #   member.avatar.icon # => 'smiling'
     #