Appease scalastyle with a newline at the end of the file

Author: srowen

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

@@ -133,4 +133,4 @@ object AddExchange extends Rule[SparkPlan] {
         operator.withNewChildren(repartitionedChildren)
       }
   }
-}
+}