04.08: log protocol discriminators and message types by name

On incoming 04.08 messages, we log only the protocol discriminator in
decimal. Enhance: log pdisc and message type in hex, and also log the
protocol and message type as human readable string.

Also adjust the msc_vlr tests' log statements for wrapped rx/tx functions
of dtap from/to the MS.

Adjust the expected output of msc_vlr_tests.

Change-Id: Ida205d217e304337d816b14fd15e2ee435e7397d
Depends: libosmocore change-id I0fca8e95ed5c2148b1a7440eff3fc9c7583898df
diff --git a/tests/msc_vlr/msc_vlr_test_hlr_timeout.err b/tests/msc_vlr/msc_vlr_test_hlr_timeout.err
index 7c04f46..f83cc29 100644
--- a/tests/msc_vlr/msc_vlr_test_hlr_timeout.err
+++ b/tests/msc_vlr/msc_vlr_test_hlr_timeout.err
@@ -1,10 +1,10 @@
 ===== test_hlr_timeout_lu_auth_info
 - Total time passed: 0.000000 s
 - Location Update request causes a GSUP Send Auth Info request to HLR
-  rx from MS: pdisc=0x05 msg_type=0x08
+  MSC <--RAN_GERAN_A-- MS: GSM48_MT_MM_LOC_UPD_REQUEST
   new conn
 DREF unknown: MSC conn use + 1 == 1
-DRLL Dispatching 04.08 message, pdisc=5
+DRLL Dispatching 04.08 message GSM48_MT_MM_LOC_UPD_REQUEST (0x5:0x8)
 DREF unknown: MSC conn use + 1 == 2
 DMM Subscr_Conn(901700000004620){SUBSCR_CONN_S_INIT}: Allocated
 DMM Subscr_Conn(901700000004620){SUBSCR_CONN_S_INIT}: Received Event SUBSCR_CONN_E_START
@@ -83,10 +83,10 @@
 ===== test_hlr_timeout_lu_upd_loc_result
 - Total time passed: 0.000000 s
 - Location Update request causes a GSUP LU request to HLR
-  rx from MS: pdisc=0x05 msg_type=0x08
+  MSC <--RAN_GERAN_A-- MS: GSM48_MT_MM_LOC_UPD_REQUEST
   new conn
 DREF unknown: MSC conn use + 1 == 1
-DRLL Dispatching 04.08 message, pdisc=5
+DRLL Dispatching 04.08 message GSM48_MT_MM_LOC_UPD_REQUEST (0x5:0x8)
 DREF unknown: MSC conn use + 1 == 2
 DMM Subscr_Conn(901700000004620){SUBSCR_CONN_S_INIT}: Allocated
 DMM Subscr_Conn(901700000004620){SUBSCR_CONN_S_INIT}: Received Event SUBSCR_CONN_E_START