Use double quotes

Change-Id: I6fc17bdd886b4a89397384d8b0f6ef57656a6be7
diff --git a/cicd/pipelines/tasks/task_release_cut.jenkins b/cicd/pipelines/tasks/task_release_cut.jenkins
index b95072a..332a3ac 100644
--- a/cicd/pipelines/tasks/task_release_cut.jenkins
+++ b/cicd/pipelines/tasks/task_release_cut.jenkins
@@ -64,7 +64,7 @@
                        """
 
                     for (board in boards) {
-                        def unstableBspSnapshotName = getLatestSnapshot('unstable-bsp-${board}')
+                        def unstableBspSnapshotName = getLatestSnapshot("unstable-bsp-${board}")
                         def releasedBspSnapshotName = "${releaseName}-bsp-${board}-${stamp}"
 
                         sh """