Correct use of `$wpdb->prepare()` to resolve PHP warning "Missing argument 2...

Correct use of `$wpdb->prepare()` to resolve PHP warning "Missing argument 2 for wpdb::prepare(), called in /wp-content/plugins/wp-cron-control/wp-cron-control.php on line 291 and defined in /wp-includes/wp-db.php...."

wp-cron-control.php

@@ -288,7 +288,7 @@ class WP_Cron_Control {
 		global $wpdb;
 
 		// grab all scheduled posts from posts table
-		$sql = $wpdb->prepare( "SELECT ID, post_date_gmt FROM $wpdb->posts WHERE post_status = 'future' " );
+		$sql = $wpdb->prepare( "SELECT ID, post_date_gmt FROM $wpdb->posts WHERE post_status = %s", 'future' );
 		$results = $wpdb->get_results( $sql );
 		$return = true;