Fix an invalid type for the `$section` parameter in the `do_settings_fields()` DocBlock.

Props ipm-frommen.
See #30098.


git-svn-id: https://develop.svn.wordpress.org/trunk@30018 602fd350-edb4-49c9-b593-d223f7449a82
Fix the `$location` parameter type in the `unregister_nav_menu()` DocBlock.

`$location` is a string, not an array.

Props ipm-frommen.
Fixes #30098.


git-svn-id: https://develop.svn.wordpress.org/trunk@30019 602fd350-edb4-49c9-b593-d223f7449a82
Users screen in network admin:
* Remove unused $key variables.
* Rename $val to $user_id for clarity.

props ipm-frommen.
fixes #30096.

git-svn-id: https://develop.svn.wordpress.org/trunk@30020 602fd350-edb4-49c9-b593-d223f7449a82