Fix checkstyle

Change-Id: I6a46aef7cf9ce81d1aebd1072fd45bb75cced3bb

Author: jojochuang

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSDirAttrOp.java

@@ -23,7 +23,6 @@
 import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.fs.permission.PermissionStatus;
 import org.apache.hadoop.hdfs.DFSUtil;
-import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.SnapshotManager;
 import org.junit.Test;
 import org.mockito.Mockito;