Wrongly called file_update hook

Hey there,

if you transliterate files over the backend (admin/config/media/file-system/transliteration) you will get the following error message:

Fatal error: Unsupported operand types in /path/to/drupal/sites/all/modules/contrib/file_entity/file_entity.file.inc on line 103

I know that this error is coming from another module, but it mainly occurs, because the hook is used in a wrong manner.

If an update hook is called an "original" is always used in all of Drupals internals and should be provided here, too.
Since natural methods of doing so are not used (avoiding file_save()) it needs to be done manually. Also to follow the file_save() function's behavior "module_invoke_all('entity_update', $file, 'file');" should be called, too.

Anyways, I think the best way to this issue is to just call file_save().
The comment saying "Don't use file_save() as it modifies the timestamp." is not a real reason, because the file itself is modified. The date should be therefore update.

Please consider this change back to the way it should be.

func0der