Improve some wp-admin/includes/class-wp-filesystem-*.php docs for @param.

See #30799.


git-svn-id: https://develop.svn.wordpress.org/trunk@30978 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/class-wp-filesystem-direct.php

@@ -394,7 +394,7 @@ class WP_Filesystem_Direct extends WP_Filesystem_Base {
 	/**
 	 * @param string $path
 	 * @param bool $recursive
-	 * @return type
+	 * @return bool
 	 */
 	public function rmdir($path, $recursive = false) {
 		return $this->delete($path, $recursive);