Stop filling efficiency histograms in TRT monitoring

This is a continuation of what I started in !66471 (merged). Back then, I thought all our efficiency values equal 1 because we did not have any holes on track (because the m_useHoleFinder was set to false somewhere). Now I realize that m_useHoleFinder was actually set to true, and all efficiencies equalled 1 for a different reason, namely because the const Trk::TrackStates holes vector was always empty. This means that we are trying to perform a fruitless loop over this empty vector and another loop (a normal one) over hits on track, incrementing both the efficiency numerator and the denominator by 1 for each hit, which always leads to a 100% efficiency. Which, in turn, renders these histograms useless (sort of). By setting m_useHoleFinder to false in the current MR we stop performing both loops. Efficiency histograms will not be filled for each hit, and the precious CPU time will be saved.