Reverting content features is broken

In the features updating code in update_api_features_revert() you invoke all features_revert functions that are necessary by running:

$result = module_invoke($component, 'features_revert', $module);

If the return value is TRUE then all is good. However in features.content.inc...

function content_features_revert($module) {
  content_features_rebuild($module);
}

There's no return value.

So one of two things...
1. either features module needs to change so that there's always a return value
2. change update_api so that it only fails on a FALSE return value, not null

The attached patch fixes it for #2. But I think #1 would probably be cleaner and more consistent within features.