HBASE-10223 [VisibilityController] cellVisibility presence check on Delete mutation is wrong

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1553014 13f79535-47bb-0310-9956-ffa450edef68

hbase-server/src/main/java/org/apache/hadoop/hbase/security/visibility/VisibilityController.java

@@ -683,7 +683,7 @@ public class VisibilityController extends BaseRegionObserver implements MasterOb
             }
           }
         }
-      } else {
+      } else if (cellVisibility != null) {
         // CellVisibility in a Delete is not legal! Fail the operation
         miniBatchOp.setOperationStatus(i, new OperationStatus(SANITY_CHECK_FAILURE,
             "CellVisibility cannot be set on Delete mutation"));