Fix scala style.

Author: beliefer

sql/core/src/main/scala/org/apache/spark/sql/execution/offset.scala

@@ -20,8 +20,7 @@ package org.apache.spark.sql.execution
 import org.apache.spark.rdd.RDD
 import org.apache.spark.serializer.Serializer
 import org.apache.spark.sql.catalyst.InternalRow
-import org.apache.spark.sql.catalyst.expressions.SortOrder
-import org.apache.spark.sql.catalyst.expressions.Attribute
+import org.apache.spark.sql.catalyst.expressions.{Attribute, SortOrder}
 import org.apache.spark.sql.catalyst.plans.physical.{Partitioning, SinglePartition}