HBASE-21959 - CompactionTool should close the store it uses for compacting files, in order to properly archive compacted files.

Reapply without unit test

Change-Id: If852529e79274a77eb08cac13936f02776232608
Signed-off-by: Xu Cang <xucang@apache.org>
Amending-Author: Andrew Purtell <apurtell@apache.org>

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

@@ -171,6 +171,8 @@ public class CompactionTool extends Configured implements Tool {
           }
         }
       } while (store.needsCompaction() && !compactOnce);
+      //We need to close the store properly, to make sure it will archive compacted files
+      store.close();
     }
 
     /**