Changing to not use the path if the label has already been set.  

The path can be more than 255 characters which messes with Fedora...

If the path is long (which happens with browse-everything/Box integration) you get the following error...
ERROR 2014-08-07 21:38:35.383 [http-apr-8080-exec-25] (DatastreamResource) Unexpected error fulfilling REST API request
org.fcrepo.server.errors.ValidationException: Datastream label is too long. Maximum length is 255 characters.

The browse-everything integration passes back a file name which is set to the label here: https://github.com/projecthydra/sufia/blob/master/app/controllers/concerns/sufia/files_controller/browse_everything.rb#L26