Add missing doc blocks to wp-admin/includes/*.

Fix some egregious uses of tabbing.
Some functions can simply return `apply_filters(...)` instead of setting a variable that is immediately returned.

See #32444.


git-svn-id: https://develop.svn.wordpress.org/trunk@32654 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/network.php

@@ -157,6 +157,8 @@ include( ABSPATH . 'wp-admin/admin-header.php' );
  * @since 3.0.0
  *
  * @global bool $is_apache
+ *
+ * @param WP_Error $errors
  */
 function network_step1( $errors = false ) {
 	global $is_apache;
@@ -336,6 +338,8 @@ function network_step1( $errors = false ) {
  * @since 3.0.0
  *
  * @global wpdb $wpdb
+ *
+ * @param WP_Error $errors
  */
 function network_step2( $errors = false ) {
 	global $wpdb;