Fix a variable name

Author: JackMc

lib/action_controller/caching/pages.rb

@@ -160,7 +160,7 @@ def cache_path(path, extension = nil)
             unnormalized_path = File.join(normalized_cache_directory, cache_file(path, extension))
             normalized_path = File.expand_path(unnormalized_path)
 
-            relative_path if normalized_path.start_with?(normalized_cache_directory)
+            normalized_path if normalized_path.start_with?(normalized_cache_directory)
           end
 
           def delete(path)