Since commit defc97ec16 ("Msg2 and Msg3 at gNB: check allocation before
committing to Msg2"), the scheduler calculate Msg2/Msg3 frame/slot
before allocation of Msg2, and not when receiving Msg1. It also respects
the RA response window correctly.
Correspondingly, we don't need to calculate here if the RACH.indication
is within the time window. The scheduler will do this.