Subscription: fix hasNext method in tablet batch to support multiple tsfile in the same batch (#14715)

Author: VGalaxies

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/subscription/event/batch/SubscriptionPipeTabletEventBatch.java

@@ -216,7 +216,7 @@ public boolean hasNext() {
         // reset
         currentTabletInsertionEventsIterator = null;
         currentTsFileInsertionEvent = null;
-        return false;
+        return hasNext();
       }
     }