Use trim() method returned value.

Strings being immutable, you need to use the trim() method return value.

Author: thomasleplus

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

@@ -294,7 +294,7 @@ public void testDfsAdminCmd() throws Exception {
       restore = fsi.getStorage().getRestoreFailedStorage();
       assertTrue("After check call restore is " + restore, restore);
       String commandOutput = cmdResult.getCommandOutput();
-      commandOutput.trim();
+      commandOutput = commandOutput.trim();
       assertTrue(commandOutput.contains("restoreFailedStorage is set to true"));