mm_s3: files not deleted from 'files' table, when user deletes node

I have a configuration that harvests a particular filefield and stores the files on s3.
If the user deletes a node, the file entries do not get deleted from the 'files' database table.
The attached patch to mm_s3_delete_file() fixes the problem.

function mm_s3_delete_file($item, $configuration) {
   // Delete file entry in in 'files' table
  $fid = $item['fid'];
  db_query('DELETE FROM {files} WHERE fid = "%d"', $fid); // delete entry in 'files' table
  ...
}