address review

Author: HuaHuaY

cpp/src/parquet/file_rewriter.cc

@@ -470,7 +470,7 @@ class SingleFileRewriter {
     if (current_row_group_index_ >= metadata_->num_row_groups()) {
       throw ParquetException("Trying to read row group ", current_row_group_index_,
                              " but file only has ", metadata_->num_row_groups(),
-                             " row group");
+                             " row groups");
     }
     auto row_group_reader = parquet_file_reader_->RowGroup(current_row_group_index_);
     auto page_index_reader = page_index_reader_
@@ -771,7 +771,7 @@ class GeneratedFile : public ParquetFileRewriter::Contents {
 };
 
 // ----------------------------------------------------------------------
-// ParquetFilesRewriter public API
+// ParquetFileRewriter public API
 
 ParquetFileRewriter::ParquetFileRewriter() = default;