Update Jenkinsfiles to use buildNode instead of TestNodeName

Change-Id: Ifd68d1f67d88ebf7190e733311bfc8f8f1a59a06
diff --git a/Jenkinsfile-rcordlite-topdown-build b/Jenkinsfile-rcordlite-topdown-build
index 6923c58..ccc0fe5 100644
--- a/Jenkinsfile-rcordlite-topdown-build
+++ b/Jenkinsfile-rcordlite-topdown-build
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-node ("${TestNodeName}") {
+node ("${buildNode}") {
     timeout (100) {
         try {
             stage ("Parse deployment configuration file") {