Privacy: When clicking a confirmation link for a privacy request, return a `WP_Error` object if the link has expired.

Returning a string caused a success message to be displayed instead of the correct error message.

Props desrosj.
Merges [43623] to the 4.9 branch.
Fixes #44685.
Built from https://develop.svn.wordpress.org/branches/4.9@43624


git-svn-id: http://core.svn.wordpress.org/branches/4.9@43453 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/user.php

@@ -3449,7 +3449,7 @@ function wp_validate_user_request_key( $request_id, $key ) {
 	}
 
 	if ( ! in_array( $request->status, array( 'request-pending', 'request-failed' ), true ) ) {
-		return __( 'This link has expired.' );
+		return new WP_Error( 'expired_link', __( 'This link has expired.' ) );
 	}
 
 	if ( empty( $key ) ) {

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.9.9-alpha-43622';
+$wp_version = '4.9.9-alpha-43624';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.