HDFS-7552. Change FsVolumeList toString() to fix TestDataNodeVolumeFailureToleration (Liang Xie via Colin P. McCabe)

(cherry picked from commit a4876c130f1627e59ef055e586640d1933fc49af)

(cherry picked from commit 22f72c79462c424e47610470fd48e871887ac326)

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -175,6 +175,9 @@ Release 2.6.1 - UNRELEASED
     HDFS-8863. The remaining space check in BlockPlacementPolicyDefault is
     flawed. (Kihwal Lee via yliu)
 
+    HDFS-7552. Change FsVolumeList toString() to fix
+    TestDataNodeVolumeFailureToleration (Liang Xie via Colin P. McCabe)
+
 Release 2.6.0 - 2014-11-18
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsVolumeList.java

@@ -216,7 +216,7 @@ class FsVolumeList {
 
   @Override
   public String toString() {
-    return volumes.toString();
+    return Arrays.toString(volumes.get());
   }
 
   /**