Revert "Modify to prepare for further optimization."

This reverts commit ebb1241.

Author: ueshin

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/objects/objects.scala

@@ -205,8 +205,9 @@ case class Invoke(
 
     val evaluateArguments = if (arguments.nonEmpty) {
       s"""
-        if (!${obj.isNull}) {
+        if (!${ev.isNull}) {
           $argCode
+          ${ev.isNull} = $resultIsNull;
         }
       """
     } else {
@@ -253,8 +254,8 @@ case class Invoke(
 
     val code = s"""
       ${obj.code}
+      boolean ${ev.isNull} = ${obj.isNull};
       $evaluateArguments
-      boolean ${ev.isNull} = ${obj.isNull} || $resultIsNull;
       $javaType ${ev.value} = ${ctx.defaultValue(dataType)};
       if (!${ev.isNull}) {
         $evaluate