Simplify scope of varibles as needed

Author: kiszk

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

@@ -217,12 +217,11 @@ case class MapElementsExec(
   }
 
   override def doConsume(ctx: CodegenContext, input: Seq[ExprCode], row: ExprCode): String = {
-    val inType = if (child.output.length == 1) child.output(0).dataType else NullType
-    val outType = outputObjAttr.dataType
     val (funcClass, methodName) = func match {
       case m: MapFunction[_, _] => classOf[MapFunction[_, _]] -> "call"
       case _ =>
-        (inType, outType) match {
+        (if (child.output.length == 1) child.output(0).dataType else NullType,
+         outputObjAttr.dataType) match {
           // if a pair of an argument and return types is one of specific types
           // whose specialized method (apply$mc..$sp) is generated by scalac,
           // Catalyst generated a direct method call to the specialized method.