Call-time pass-by-reference has been deprecated in drupal_load()

The enclosed patch prevents the following error message from being displayed:

Deprecated function: Call-time pass-by-reference has been deprecated in drupal_load() (line 933 of /home/simor/Zend/workspaces/DefaultWorkspace7/Scratchpads-2.0/includes/bootstrap.inc).

The function declaration already states that $ar_exif is passed by reference, so there is no need to state that it should be passed by reference at runtime anyway.