Consistency pass on naming in JJB

- Name of the pipeline script when parameterized: `pipeline-script`
- Name of executor the job is running on: `build-node` (or `buildNode` if
  in a pipeline job)

Change-Id: Id069a2d3f17dc5dbd7259e0ed046b72017da0538
diff --git a/jjb/pipeline/xos-core.groovy b/jjb/pipeline/xos-core.groovy
index 99aacb1..b6001fb 100644
--- a/jjb/pipeline/xos-core.groovy
+++ b/jjb/pipeline/xos-core.groovy
@@ -19,7 +19,7 @@
 
   /* no label, executor is determined by JJB */
   agent {
-    label "${params.executorNode}"
+    label "${params.buildNode}"
   }
 
   stages {