use better file constant.

Author: bangpound

kernel.drush.inc

@@ -46,7 +46,7 @@ function drush_kernel_app($command = '') {
 
   // Include the run in a different file so that PHP versions < 5.3 do not fail
   // parsing the file.
-  require_once(dirname(__FILE__) . '/kernel.drush.run.inc');
+  require_once(__DIR__ .'/kernel.drush.run.inc');
 
   // Run the console command using the given function arguments.
   return drush_kernel_app_run(func_get_args());