Fix a typo in k8s upgrade pipeline

getPillar call arg should be pepperEnv instead of
venvPepper

Change-Id: If0c015a5ed82f3e672d8e0eae04870c19b32180d
diff --git a/k8s-upgrade-pipeline.groovy b/k8s-upgrade-pipeline.groovy
index 19cf47d..a09ae85 100644
--- a/k8s-upgrade-pipeline.groovy
+++ b/k8s-upgrade-pipeline.groovy
@@ -269,7 +269,7 @@
 
 def containerDenabled(pepperEnv, target) {
     def salt = new com.mirantis.mk.Salt()
-    return salt.getPillar(venvPepper, target, "kubernetes:common:containerd:enabled"
+    return salt.getPillar(pepperEnv, target, "kubernetes:common:containerd:enabled"
                           )["return"][0].values()[0].toBoolean()
 }