set default heat stack name

Change-Id: I2054b05555a86fdc9f980b0ecb294c054e0ab8a9
diff --git a/mk-k8s-simple-deploy-pipeline.groovy b/mk-k8s-simple-deploy-pipeline.groovy
index 84897cb..641283d 100644
--- a/mk-k8s-simple-deploy-pipeline.groovy
+++ b/mk-k8s-simple-deploy-pipeline.groovy
@@ -34,7 +34,7 @@
     def openstackEnv = "${env.WORKSPACE}/venv"
 
     if (HEAT_STACK_NAME == "") {
-	HEAT_STACK_NAME = "mk-k8s-simple-b" + BUILD_NUMBER
+	HEAT_STACK_NAME = JOB_NAME + "-b" + BUILD_NUMBER
     }
 
     stage ('Download Heat templates') {