Fix broken code snippet with wrong variable name

The javascript sample used `durableOrchestrationStatus` to initially store the return value, but later used `status` to refer to same variable.

Author: xinyi-joffre

articles/azure-functions/durable/durable-functions-custom-orchestration-status.md

@@ -128,7 +128,7 @@ module.exports = async function(context, req) {
     context.log(`Started orchestration with ID = '${instanceId}'.`);
 
     let durableOrchestrationStatus = await client.getStatus(instanceId);
-    while (status.customStatus.toString() !== "London") {
+    while (durableOrchestrationStatus.customStatus.toString() !== "London") {
         await new Promise((resolve) => setTimeout(resolve, 200));
         durableOrchestrationStatus = await client.getStatus(instanceId);
     }