Also check resolution myself

Author: kiszk

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/object.scala

@@ -43,7 +43,7 @@ object CatalystSerde {
   def generateObjAttr[T : Encoder]: Attribute = {
     val deserializer = encoderFor[T].deserializer
     val dataType = deserializer.dataType
-    val nullable = if (deserializer.childrenResolved) {
+    val nullable = if (deserializer.resolved) {
       deserializer.nullable
     } else {
       // Since deserializer is not resolved here, cannot access deserializer.nullable.