Fixing check for patchset build in scale test

Change-Id: I8f3ded8471bebd6a01af107c1c966626f6ed6654
diff --git a/jjb/pipeline/voltha-scale-test.groovy b/jjb/pipeline/voltha-scale-test.groovy
index f50d9d4..806f7bf 100644
--- a/jjb/pipeline/voltha-scale-test.groovy
+++ b/jjb/pipeline/voltha-scale-test.groovy
@@ -159,7 +159,7 @@
     stage('Build patch') {
       when {
         expression {
-          return env.hasProperty("GERRIT_PROJECT") && env.GERRIT_PROJECT != ""
+          return params.GERRIT_PROJECT
         }
       }
       steps {