Fix swapped variables in error message (elastic#44300)

The alias name and index were in the incorrect order in this error
message. This commit corrects the order.

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/indexlifecycle/WaitForRolloverReadyStep.java

@@ -98,7 +98,7 @@ public void evaluateCondition(IndexMetaData indexMetaData, Listener listener) {
         // Similarly, if isWriteIndex is false (see note above on false vs. null), we can't roll over this index, so error out.
         if (Boolean.FALSE.equals(isWriteIndex)) {
             listener.onFailure(new IllegalArgumentException(String.format(Locale.ROOT,
-                "index [%s] is not the write index for alias [%s]", rolloverAlias, indexMetaData.getIndex().getName())));
+                "index [%s] is not the write index for alias [%s]", indexMetaData.getIndex().getName(), rolloverAlias)));
         }
 
         RolloverRequest rolloverRequest = new RolloverRequest(rolloverAlias, null);