HDFS-11011. Add unit tests for HDFS command 'dfsadmin -set/clrSpaceQuota'. Contributed by Xiaobing Zhou.

(cherry picked from commit 85f6fec0370b3cd94d6c2f19920c0b6d33f127c6)
(cherry picked from commit c2ba4b650168be4fad7ffdb546b8a0d985268393)

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/tools/TestDFSAdmin.java

@@ -56,6 +56,9 @@ import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
+/**
+ * set/clrSpaceQuote are tested in {@link org.apache.hadoop.hdfs.TestQuota}.
+ */
 public class TestDFSAdmin {
   private Configuration conf = null;
   private MiniDFSCluster cluster;