Added comment and checkstyle fix

Author: gvramana

sql/hive/src/main/scala/org/apache/spark/sql/hive/TableReader.scala

@@ -55,7 +55,7 @@ class HadoopTableReader(
     @transient relation: MetastoreRelation,
     @transient sc: HiveContext,
     @transient hiveExtraConf: HiveConf)
-  extends TableReader {	
+  extends TableReader {
 
   // Choose the minimum number of splits. If mapred.map.tasks is set, then use that unless
   // it is smaller than what Spark suggests.

sql/hive/src/main/scala/org/apache/spark/sql/hive/execution/HiveTableScan.scala

@@ -64,11 +64,14 @@ case class HiveTableScan(
     BindReferences.bindReference(pred, relation.partitionKeys)
   }
 
+  // Create a local copy of hiveconf,so that scan specific modifications should not impact 
+  // other queries
   @transient
   private[this] val hiveExtraConf = new HiveConf(context.hiveconf)
 
   @transient
-  private[this] val hadoopReader = new HadoopTableReader(attributes, relation, context, hiveExtraConf)
+  private[this] val hadoopReader = 
+    new HadoopTableReader(attributes, relation, context, hiveExtraConf)
 
   private[this] def castFromString(value: String, dataType: DataType) = {
     Cast(Literal(value), dataType).eval(null)