Uniform messages of exiting threads

common/utils/msc/msc.c

openair2/ENB_APP/enb_app.c

openair2/ENB_APP/flexran_agent.c

openair2/RRC/LITE/rrc_UE.c

openair2/RRC/LITE/rrc_eNB.c

openair2/X2AP/x2ap.c

openair3/GTPV1-U/gtpv1u_eNB.c

openair3/GTPV1-U/gtpv1u_task.c

openair3/S1AP/s1ap_eNB.c

openair3/SCTP/sctp_eNB_task.c

openair3/TEST/EPC_TEST/play_scenario_s1ap.c

openair3/UDP/udp_eNB_task.c

targets/RT/USER/lte-enb.c

targets/RT/USER/lte-softmodem.c