IDPVM: Tweak definition of unlinked fakes
Using the probability match even with unlinked fakes will help us get the full picture for the MC-based tracking fake rate.
In more details:
Before this MR, 2 TEfficiencies are created:
- N. of Unlinked / N. of tracks
- N. of Linked tracks w/ prob < 0.5 / N. of Linked tracks
This MR changes the first one to
- N. of Unlinked w/ prob < 0.5 / N. of Unlinked
The previous TEfficiency can be recovered, since TEfficiency objects contain both the denominator & numerator histogram. Moreover, this definition is also safe to use even in standard truth sample, since in the code there's a nan check when deciding if a track is fake or not with the probability.