HBASE-7799 reassigning region stuck in open still may not work correctly due to leftover ZK node

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1446784 13f79535-47bb-0310-9956-ffa450edef68

hbase-server/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java

@@ -2806,6 +2806,12 @@ public class AssignmentManager extends ZooKeeperListener {
             + " since it is not opening on the dead server any more: " + sn);
           it.remove();
         } else {
+          try{
+            // Delete the ZNode if exists
+            ZKAssign.deleteNodeFailSilent(watcher, hri);
+          } catch (KeeperException ke) {
+            server.abort("Unexpected ZK exception deleting node " + hri, ke);
+          }
           // Mark the region closed and assign it again by SSH
           regionStates.updateRegionState(hri, RegionState.State.CLOSED);
         }