[Docs] Fix inconsistent example in spot instance documentation (#3996)

* [Docs] Fix inconsistent example in spot instance documentation

Fixes #3995

* Update docs/source/serving/spot-policy.rst

Co-authored-by: Zhanghao Wu <zhanghao.wu@outlook.com>

---------

Co-authored-by: Zhanghao Wu <zhanghao.wu@outlook.com>

docs/source/serving/spot-policy.rst

@@ -96,7 +96,7 @@ When the service is up, we can check the status of the service and the replicas
     http-server   3   1        -                          1 mins ago  1x GCP(vCPU=2)        PROVISIONING  us-east1     
     http-server   4   1        -                          1 min ago   1x GCP(vCPU=2)        PROVISIONING  us-central1
 
-When the required number of spot replicas are not available, SkyServe will provision the number of on-demand replicas needed to meet the target number of replicas. For example, when the target number is 2 and only 1 spot replica is ready, SkyServe will provision 1 on-demand replica to meet the target number of replicas. 
+When the required number of spot replicas are not available, SkyServe will provision on-demand replicas to meet the target number of replicas. For example, when the target number is 2 and no spot replicas are ready, SkyServe will provision 2 on-demand replicas to meet the target number of replicas. 
 
 .. code-block:: console
 
@@ -157,4 +157,4 @@ Eventually, when the spot availability is back, SkyServe will automatically scal
     Service Replicas
     SERVICE_NAME  ID  VERSION  ENDPOINT                   LAUNCHED     RESOURCES             STATUS         REGION       
     http-server   2   1        http://34.68.226.193:8081  10 mins ago  1x GCP([Spot]vCPU=2)  READY          us-central1  
-    http-server   5   1        http://34.121.49.94:8081   1 min ago    1x GCP([Spot]vCPU=2)  READY          us-central1
+    http-server   5   1        http://34.121.49.94:8081   1 min ago    1x GCP([Spot]vCPU=2)  READY          us-central1