[MINOR] remove unused generics type (#2163)

diff --git a/hudi-client/hudi-client-common/src/main/java/org/apache/hudi/table/action/commit/AbstractMergeHelper.java b/hudi-client/hudi-client-common/src/main/java/org/apache/hudi/table/action/commit/AbstractMergeHelper.java
index 1bbffad..8c92b00 100644
--- a/hudi-client/hudi-client-common/src/main/java/org/apache/hudi/table/action/commit/AbstractMergeHelper.java
+++ b/hudi-client/hudi-client-common/src/main/java/org/apache/hudi/table/action/commit/AbstractMergeHelper.java
@@ -94,7 +94,7 @@
                                                                                                Schema readSchema, boolean externalSchemaTransformation) throws IOException {
     Path externalFilePath = new Path(baseFile.getBootstrapBaseFile().get().getPath());
     Configuration bootstrapFileConfig = new Configuration(table.getHadoopConf());
-    HoodieFileReader<GenericRecord> bootstrapReader = HoodieFileReaderFactory.<T, GenericRecord>getFileReader(bootstrapFileConfig, externalFilePath);
+    HoodieFileReader<GenericRecord> bootstrapReader = HoodieFileReaderFactory.<GenericRecord>getFileReader(bootstrapFileConfig, externalFilePath);
     Schema bootstrapReadSchema;
     if (externalSchemaTransformation) {
       bootstrapReadSchema = bootstrapReader.getSchema();
diff --git a/hudi-client/hudi-spark-client/src/main/java/org/apache/hudi/table/action/commit/SparkMergeHelper.java b/hudi-client/hudi-spark-client/src/main/java/org/apache/hudi/table/action/commit/SparkMergeHelper.java
index 697b5ac..2d130e3 100644
--- a/hudi-client/hudi-spark-client/src/main/java/org/apache/hudi/table/action/commit/SparkMergeHelper.java
+++ b/hudi-client/hudi-spark-client/src/main/java/org/apache/hudi/table/action/commit/SparkMergeHelper.java
@@ -76,7 +76,7 @@
     }
 
     BoundedInMemoryExecutor<GenericRecord, GenericRecord, Void> wrapper = null;
-    HoodieFileReader<GenericRecord> reader = HoodieFileReaderFactory.<T, GenericRecord>getFileReader(cfgForHoodieFile, mergeHandle.getOldFilePath());
+    HoodieFileReader<GenericRecord> reader = HoodieFileReaderFactory.<GenericRecord>getFileReader(cfgForHoodieFile, mergeHandle.getOldFilePath());
     try {
       final Iterator<GenericRecord> readerIterator;
       if (baseFile.getBootstrapBaseFile().isPresent()) {
diff --git a/hudi-common/src/main/java/org/apache/hudi/io/storage/HoodieFileReaderFactory.java b/hudi-common/src/main/java/org/apache/hudi/io/storage/HoodieFileReaderFactory.java
index 3c97b36..ff559c5 100644
--- a/hudi-common/src/main/java/org/apache/hudi/io/storage/HoodieFileReaderFactory.java
+++ b/hudi-common/src/main/java/org/apache/hudi/io/storage/HoodieFileReaderFactory.java
@@ -19,7 +19,6 @@
 package org.apache.hudi.io.storage;
 
 import org.apache.hudi.common.fs.FSUtils;
-import org.apache.hudi.common.model.HoodieRecordPayload;
 
 import org.apache.avro.generic.IndexedRecord;
 import org.apache.hadoop.conf.Configuration;
@@ -33,8 +32,7 @@
 
 public class HoodieFileReaderFactory {
 
-  public static <T extends HoodieRecordPayload, R extends IndexedRecord> HoodieFileReader<R> getFileReader(
-      Configuration conf, Path path) throws IOException {
+  public static <R extends IndexedRecord> HoodieFileReader<R> getFileReader(Configuration conf, Path path) throws IOException {
     final String extension = FSUtils.getFileExtension(path.toString());
     if (PARQUET.getFileExtension().equals(extension)) {
       return newParquetFileReader(conf, path);
@@ -46,13 +44,11 @@
     throw new UnsupportedOperationException(extension + " format not supported yet.");
   }
 
-  private static <T extends HoodieRecordPayload, R extends IndexedRecord> HoodieFileReader<R> newParquetFileReader(
-      Configuration conf, Path path) throws IOException {
+  private static <R extends IndexedRecord> HoodieFileReader<R> newParquetFileReader(Configuration conf, Path path) {
     return new HoodieParquetReader<>(conf, path);
   }
 
-  private static <T extends HoodieRecordPayload, R extends IndexedRecord> HoodieFileReader<R> newHFileFileReader(
-      Configuration conf, Path path) throws IOException {
+  private static <R extends IndexedRecord> HoodieFileReader<R> newHFileFileReader(Configuration conf, Path path) throws IOException {
     CacheConfig cacheConfig = new CacheConfig(conf);
     return new HoodieHFileReader<>(conf, path, cacheConfig);
   }