Remove old RNTI at MAC layer when Msg3 RRCSetupRequest carries ng-5G-S-TMSI-Part1
Currently, OAI CN5G raises an error when it receives a TMSI (instead of a random value) on the Initial Access, and does not reply to the gNB:
[2022-12-05T15:51:48.237594] [AMF] [amf_n1 ] [error] No Security Context found
So, we need to remove old RNTI at MAC layer when Msg3 RRCSetupRequest carries ng-5G-S-TMSI-Part1, otherwise the gNB will become full of UEs (COTS UE triggers new RA periodically)
For now, we are removing the UEs from RRC at MAC the same way as it is done in other places in the same source file. A proper F1 implementation to remove the UEs from RRC at MAC will come later.