Use better way to check ready (#17816)

* update ready script

Signed-off-by: Xiang Dai <764524258@qq.com>

* update script

Signed-off-by: Xiang Dai <764524258@qq.com>

incubator/zookeeper/Chart.yaml

@@ -1,7 +1,7 @@
 apiVersion: v1
 name: zookeeper
 home: https://zookeeper.apache.org/
-version: 2.1.0
+version: 2.1.1
 appVersion: 3.5.5
 kubeVersion: "^1.10.0-0"
 description: Centralized service for maintaining configuration information, naming,

incubator/zookeeper/templates/config-script.yaml

@@ -12,7 +12,7 @@ metadata:
 data:
     ok: |
       #!/bin/sh
-      echo ruok | nc 127.0.0.1 ${1:-2181}
+      zkServer.sh status
 
     ready: |
       #!/bin/sh