Docs: Use more consistent descriptions for void|false return values.

See #51800.
Built from https://develop.svn.wordpress.org/trunk@49935


git-svn-id: http://core.svn.wordpress.org/trunk@49634 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/user.php

@@ -1537,7 +1537,7 @@ function sanitize_user_field( $field, $value, $user_id, $context ) {
  * @since 3.0.0
  *
  * @param object|WP_User $user User object or database row to be cached
- * @return void|false Returns false on failure.
+ * @return void|false Void on success, false on failure.
  */
 function update_user_caches( $user ) {
 	if ( $user instanceof WP_User ) {