Docs: In various @return tags, list the expected type first, instead of WP_Error.

See #48303.
Built from https://develop.svn.wordpress.org/trunk@46696


git-svn-id: http://core.svn.wordpress.org/trunk@46496 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/post.php

@@ -1405,7 +1405,8 @@ function get_post_types( $args = array(), $output = 'names', $operator = 'and' )
  *     @type string      $_edit_link            FOR INTERNAL USE ONLY! URL segment to use for edit link of
  *                                              this post type. Default 'post.php?post=%d'.
  * }
- * @return WP_Post_Type|WP_Error The registered post type object, or an error object.
+ * @return WP_Post_Type|WP_Error The registered post type object on success,
+ *                               WP_Error object on failure.
  */
 function register_post_type( $post_type, $args = array() ) {
 	global $wp_post_types;