Correct $wp_registered_widget_controls global reference in wp_register_sidebar_widget()

[upadalavipul]

the function in define global variable is $wp_registered_widget_controls but comments in define$wp_register_widget_defaults

[SergeyBiryukov]

Introduced in [30776]. Looks like $wp_register_widget_defaults never existed. The description should probably be updated as well.

@upadalavipul Thanks for the patch! In the future, it would be helpful to provide a more descriptive summary when creating Trac tickets. "Needs documents improvement" is exceptionally vague :)

I've gone ahead and updated the summary here to demonstrate what you should be aiming for.

[obenland]

In 41798:

Widgets: Update globals documentation.

It doesn't look like wp_register_sidebar_widget() ever used a global named $wp_register_widget_defaults. It does however make use of $wp_registered_widget_controls now.

See [8960], [30776].

Props upadalavipul.
Fixes #41592.