Populate methods now always have 'customization' argument because

deserialize-method(s) of nested records may generate another
populate methods that require 'customization' (at least for compilation).

This commits contains the fix.

fastserde/avro-fastserde-tests-common/src/test/java/com/linkedin/avro/fastserde/FastSpecificDeserializerGeneratorTest.java

@@ -48,7 +48,6 @@
 import org.testng.Assert;
 import org.testng.annotations.BeforeTest;
 import org.testng.annotations.DataProvider;
-import org.testng.annotations.Ignore;
 import org.testng.annotations.Test;
 import org.testng.collections.Lists;
 import org.testng.internal.collections.Pair;
@@ -882,7 +881,6 @@ void deserializeNullableFieldsPreviouslySerializedAsNotNull(boolean useFastSeria
     Assert.assertEquals(outerRecord2.toString(), outerRecord1.toString());
   }
 
-  @Ignore
   @Test(groups = {"deserializationTest"})
   void deserializeWithSchemaMissingDeeplyNestedRecord() throws IOException {
     // duplicates prepare() just in case - .avsc files used here assume FIELDS_PER_POPULATION_METHOD is 2

fastserde/avro-fastserde/src/main/java/com/linkedin/avro/fastserde/FastDeserializerGenerator.java

@@ -370,16 +370,16 @@ private void processRecord(JVar recordSchemaVar, String recordName, final Schema
         popMethod._throws(IOException.class);
         if (recordAction.getShouldRead()) {
           popMethod.param(recordClass, recordName);
-          popMethod.param(codeModel.ref(DatumReaderCustomization.class), VAR_NAME_FOR_CUSTOMIZATION);
         }
+        popMethod.param(codeModel.ref(DatumReaderCustomization.class), VAR_NAME_FOR_CUSTOMIZATION);
         popMethod.param(Decoder.class, DECODER);
         popMethodBody = popMethod.body();
 
         JInvocation invocation = methodBody.invoke(popMethod);
         if (recordAction.getShouldRead()) {
           invocation.arg(JExpr.direct(recordName));
-          invocation.arg(customizationSupplier.get());
         }
+        invocation.arg(customizationSupplier.get());
         invocation.arg(JExpr.direct(DECODER));
       }
       FieldAction action = seekFieldAction(recordAction.getShouldRead(), field, actionIterator);