privacy padlocks not shown if content type name contains an underscore

Hi,

I had created a content type in my Drupal install named 'company_profile'. I changed the CCK field privacy settings to allow privacy options for this content type.
However, the padlocks never showed up.

Digging into the code, i found that the content type name is retrieved by the following code:

$node_name_array = explode('_', $form_id);

This broke the functionality for my content type. However, a few lines above the content type name is retrieved in another way:

$form['#node']->type

The attached patch changes the code so it uses the 2nd method to retrieve the name of the content type of the currently watched form, fixing the bug i encountered.

Please review the patch, and commit if it doesn't break anything. I know for me it didn't.