Make FindVDT.cmake compatible with ROOT's FindVdt.cmake
The builds in lhcb-lcg-dev4lhcb are failing because we (implicitly) end up using a mix of FindVdt.cmake
from ROOT and FindVDT.cmake
from LHCb.
I modified FindVDT.cmake
to avoid destructive interference with ROOT version.
An alternative fix would be to use directly FindVdt.cmake
from ROOT, but that requires a more recent version of ROOT or to copy the file in LHCb and to replace all uses of VDT::vdt
with VDT::vdt
.