tools/wireshark: simplify buffer read
tools/wireshark: simplify buffer read

Change-Id: Icad17cb49841614af4e94be0885e5c9c12c50091
Reviewed-on: http://gerrit.aldebaran.lan/88920
Reviewed-by: vincent.palancher <f8ff75e1c61314c499fafa8de0d9e004e87e66b0@external.softbankrobotics.com>
Reviewed-by: jmonnon <8898eaf233516e520f996a244ca8a12d20f948b1@aldebaran.com>
Tested-by: lguegan <78ec28e1fc7cd0c64a94dbd26f9a4494d11b4c11@aldebaran-robotics.com>

aldebaran/libqi,aldebaran/libqi,aldebaran/libqi