fix review comments

Author: zjffdu

sql/core/src/main/scala/org/apache/spark/sql/DataFrameWriter.scala

@@ -132,7 +132,6 @@ final class DataFrameWriter private[sql](df: DataFrame) {
   }
 
   /**
-<<<<<<< b72611f20a03c790b6fd341b6ffdb3b5437609ee
    * Buckets the output by the given columns. If specified, the output is laid out on the file
    * system similar to Hive's bucketing scheme.
    *

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/DataSourceStrategy.scala

@@ -141,7 +141,7 @@ private[sql] object DataSourceStrategy extends Strategy with Logging {
     case i @ logical.InsertIntoTable(
       l @ LogicalRelation(t: HadoopFsRelation, _, _), part, query, overwrite, false) =>
       val mode = if (overwrite) SaveMode.Overwrite else SaveMode.Append
-      execution.ExecutedCommand(InsertIntoHadoopFsRelation(t, query, mode, None)) :: Nil
+      execution.ExecutedCommand(InsertIntoHadoopFsRelation(t, query, mode)) :: Nil
 
     case _ => Nil
   }

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/InsertIntoHadoopFsRelation.scala

@@ -59,7 +59,7 @@ private[sql] case class InsertIntoHadoopFsRelation(
     @transient relation: HadoopFsRelation,
     @transient query: LogicalPlan,
     mode: SaveMode,
-    codec: Option[Class[_ <: CompressionCodec]])
+    codec: Option[Class[_ <: CompressionCodec]] = None)
   extends RunnableCommand {
 
   override def run(sqlContext: SQLContext): Seq[Row] = {

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/ResolvedDataSource.scala

@@ -26,7 +26,6 @@ import scala.util.{Failure, Success, Try}
 import org.apache.hadoop.fs.Path
 import org.apache.hadoop.io.compress.{CompressionCodec, CompressionCodecFactory}
 import org.apache.hadoop.util.StringUtils
-import org.apache.hadoop.io.compress.{CompressionCodec, CompressionCodecFactory}
 
 import org.apache.spark.Logging
 import org.apache.spark.deploy.SparkHadoopUtil