[rtp_rtcp] fixed namespaces lint warnings

webrtc/modules/rtp_rtcp/source/rtcp_utility.h

 /*
 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */
 
@@ skipping 469 matching lines @@
   const RtcpCommonHeader* Current();
 
  private:
   uint8_t* const _ptrBegin;
   uint8_t* const _ptrEnd;
 
   uint8_t* _ptrBlock;
 
   RtcpCommonHeader _header;
 };
-}  // RTCPUtility
+}  // namespace RTCPUtility
 }  // namespace webrtc
 #endif // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTCP_UTILITY_H_