Removed intermediate function in MM L1 Simulation

This MR removes a not really needed intermediate function, given the optimization introduced in !60266 (merged) and that the removed function checks are reproducible by simple continue statements. Now the MMT_Road::addHits is much more readable and self-consistent, as all the computation is fully available in a bunch of lines, without having to scroll up and down between the previous two functions.

Changes are also important for ATR-25528

./cc @vadamico