Apply InfoLogLevel to the logs in utilities/merge_operators/uint64add.cc

Summary:
Apply InfoLogLevel to the logs and add missing copy-right information
to  utilities/merge_operators/uint64add.cc.

Test Plan: make

Reviewers: ljin, sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27897

utilities/merge_operators/uint64add.cc

@@ -1,3 +1,8 @@
+// Copyright (c) 2013, Facebook, Inc.  All rights reserved.
+// This source code is licensed under the BSD-style license found in the
+// LICENSE file in the root directory of this source tree. An additional grant
+// of patent rights can be found in the PATENTS file in the same directory.
+
 #include <memory>
 #include "rocksdb/env.h"
 #include "rocksdb/merge_operator.h"
@@ -45,7 +50,8 @@ class UInt64AddOperator : public AssociativeMergeOperator {
       result = DecodeFixed64(value.data());
     } else if (logger != nullptr) {
       // If value is corrupted, treat it as 0
-      Log(logger, "uint64 value corruption, size: %zu > %zu",
+      Log(InfoLogLevel::ERROR_LEVEL, logger,
+          "uint64 value corruption, size: %zu > %zu",
           value.size(), sizeof(uint64_t));
     }