Fix incorrect pipeline name in routing guide (#5548)

guides/routing.md

@@ -521,7 +521,7 @@ end
 
 The above assumes there is a plug called `HelloWeb.Authentication` that performs authentication and is now part of the `:auth` pipeline.
 
-Note that pipelines themselves are plugs, so we can plug a pipeline inside another pipeline. For example, we could rewrite the `review_checks` pipeline above to automatically invoke `browser`, simplifying the downstream pipeline call:
+Note that pipelines themselves are plugs, so we can plug a pipeline inside another pipeline. For example, we could rewrite the `auth` pipeline above to automatically invoke `browser`, simplifying the downstream pipeline call:
 
 ```elixir
   pipeline :auth do