HBASE-24182 log when the region is set to closing status (#1509)

Signed-off-by: stack <stack@apache.org>

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java

@@ -1639,6 +1639,7 @@ public class HRegion implements HeapSize, PropagatingConfigurationObserver, Regi
       }
     }
     this.closing.set(true);
+    LOG.info("Closing region {}", this);
     status.setStatus("Disabling writes for close");
     try {
       if (this.isClosed()) {