HDFS-12304. Remove unused parameter from FsDatasetImpl#addVolume. Contributed by Chen Liang.

(cherry picked from commit 02e2a9b1152b0e144fcf43bec2fce26d8a6c6dbc)

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

@@ -315,7 +315,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     deletingBlock = new HashMap<String, Set<Long>>();
 
     for (int idx = 0; idx < storage.getNumStorageDirs(); idx++) {
-      addVolume(dataLocations, storage.getStorageDir(idx));
+      addVolume(storage.getStorageDir(idx));
     }
     setupAsyncLazyPersistThreads();
 
@@ -413,8 +413,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     }
   }
 
-  private void addVolume(Collection<StorageLocation> dataLocations,
-      Storage.StorageDirectory sd) throws IOException {
+  private void addVolume(Storage.StorageDirectory sd) throws IOException {
     final StorageLocation storageLocation = sd.getStorageLocation();
 
     // If IOException raises from FsVolumeImpl() or getVolumeMap(), there is