Comments: Minor adjustments to `wp_update_comment()`:

* Revert the logic of `$wp_error` checks to avoid negation.
* Clarify the return value, restore the edits from [47017].
* Update `wp_update_comment_data` filter check to allow `false` to prevent the update.

Follow-up to [48154].

See #39732.
Built from https://develop.svn.wordpress.org/trunk@48215


git-svn-id: https://core.svn.wordpress.org/trunk@47984 1a063a9b-81f0-0310-95a4-ce76da25c4cd