fix build error

Author: mgaido91

core/src/main/scala/org/apache/spark/deploy/history/FsHistoryProvider.scala

@@ -22,15 +22,14 @@ import java.util.UUID
 import java.util.concurrent.{ConcurrentHashMap, Executors, ExecutorService, Future, TimeUnit}
 import java.util.zip.{ZipEntry, ZipOutputStream}
 
+import scala.collection.JavaConverters._
 import scala.collection.mutable
 import scala.concurrent.ExecutionException
-import scala.util.Try
 import scala.xml.Node
 
 import com.google.common.io.ByteStreams
 import com.google.common.util.concurrent.{MoreExecutors, ThreadFactoryBuilder}
 import org.apache.hadoop.fs.{FileStatus, FileSystem, Path}
-import org.apache.hadoop.fs.permission.FsAction
 import org.apache.hadoop.hdfs.DistributedFileSystem
 import org.apache.hadoop.hdfs.protocol.HdfsConstants
 import org.apache.hadoop.security.AccessControlException