Fix undefined behaviour sanitizer error in RawEventDump
Addresses
workspace/build/LHCB/LHCB_HEAD/DAQ/DAQUtils/src/RawEventDump.cpp:52:22: runtime error: load of value 128, which is not a valid value for type 'BankType'
#0 0x7f7b44fb9c4d in RawEventDump::execute() /workspace/build/LHCB/LHCB_HEAD/DAQ/DAQUtils/src/RawEventDump.cpp:52
#1 0x7f7b7c6f0e9f in Algorithm::sysExecute(EventContext const&) /workspace/build/GAUDI/GAUDI_HEAD/GaudiKernel/src/Lib/Algorithm.cpp:577