Fix wrong parameter name in Galera restoration pipeline

Fixes: PROD-24216 (PROD:24216)

Change-Id: I263d672fc0f2bb079a499eadf1fe707be1aee6e2
(cherry picked from commit 9432142f0ad4e8d1f921347e151fbf84bb33251e)
diff --git a/src/com/mirantis/mk/Openstack.groovy b/src/com/mirantis/mk/Openstack.groovy
index c2236d8..33c38f0 100644
--- a/src/com/mirantis/mk/Openstack.groovy
+++ b/src/com/mirantis/mk/Openstack.groovy
@@ -616,7 +616,7 @@
     } else {
         role = "slave"
     }
-    sizeOut = salt.getReturnValues(salt.getPillar(env, testNode, "galera:${role}:members"))
+    sizeOut = salt.getReturnValues(salt.getPillar(env, minion, "galera:${role}:members"))
     expected_cluster_size = sizeOut.size()
     outlist = out['return'][0]
     resultString = outlist.get(outlist.keySet()[0]).replace("\n        ", " ").replace("    ", "").replace("Salt command execution success", "").replace("----------", "").replace(": \n", ": no value\n")