Fix gcc9 "taking address of packed member may result in an unaligned pointer value" warning
Fix the following gcc9 warning:
DAQ/MDF/MDF/MDFHeader.h:83:56: warning: taking address of packed member of 'LHCb::MDFHeader::HeaderTriggerMask' may result in an unaligned pointer value [-Waddress-of-packed-member]
83 | const unsigned int* triggerMask() const { return m_trMask; }
by not forming pointers to a packed member, but instead return them by value (which results in 16 bytes getting copied, instead of an 8 byte pointer being formed)
Edited by Marco Cattaneo