Fix scalastyle

Author: sryza

core/src/main/scala/org/apache/spark/util/collection/ChainedBuffer.scala

@@ -142,5 +142,3 @@ private[spark] class ChainedBufferOutputStream(chainedBuffer: ChainedBuffer) ext
     pos += len
   }
 }
-
-private[spark] class OffsetAndLength(var offs: Int, var len: Int)

core/src/main/scala/org/apache/spark/util/collection/ExternalSorter.scala

@@ -747,8 +747,8 @@ private[spark] class ExternalSorter[K, V, C](
       val collection = if (aggregator.isDefined) map else buffer
       val it = collection.destructiveSortedWritablePartitionedIterator(comparator)
       while (it.hasNext) {
-        val writer = blockManager.getDiskWriter(
-          blockId, outputFile, serInstance, fileBufferSize, context.taskMetrics.shuffleWriteMetrics.get)
+        val writer = blockManager.getDiskWriter(blockId, outputFile, serInstance, fileBufferSize,
+          context.taskMetrics.shuffleWriteMetrics.get)
         val partitionId = it.nextPartition()
         while (it.hasNext && it.nextPartition() == partitionId) {
           it.writeNext(writer)