fix read_amp_bytes_per_bit field size (facebook#7651)

Summary:
The field in BlockBasedTableOptions is 4 bytes:
  // Default: 0 (disabled)
  uint32_t read_amp_bytes_per_bit = 0;

Pull Request resolved: facebook#7651

Reviewed By: ltamasi

Differential Revision: D24844994

Pulled By: riversand963

fbshipit-source-id: e2695e55532256ef8996dd6939cad06987a80293

Author: hliu18

table/block_based/block_based_table_factory.cc

@@ -333,7 +333,7 @@ static std::unordered_map<std::string, OptionTypeInfo>
           OptionTypeFlags::kNone}},
         {"read_amp_bytes_per_bit",
          {offsetof(struct BlockBasedTableOptions, read_amp_bytes_per_bit),
-          OptionType::kSizeT, OptionVerificationType::kNormal,
+          OptionType::kUInt32T, OptionVerificationType::kNormal,
           OptionTypeFlags::kNone}},
         {"enable_index_compression",
          {offsetof(struct BlockBasedTableOptions, enable_index_compression),