counters: clarify documentation for MSC_CTR_CALL_* entries

Change-Id: Iad1ef917a229c3be51bd8fbe155f009f81e7d72a
diff --git a/include/osmocom/msc/gsm_data.h b/include/osmocom/msc/gsm_data.h
index ca5c38a..87629ad 100644
--- a/include/osmocom/msc/gsm_data.h
+++ b/include/osmocom/msc/gsm_data.h
@@ -83,13 +83,13 @@
 	[MSC_CTR_SMS_DELIVERED] = 		{"sms:delivered", "Total MT SMS delivery attempts."},
 	[MSC_CTR_SMS_RP_ERR_MEM] = 		{"sms:rp_err_mem", "Failed MT SMS delivery attempts (no memory)."},
 	[MSC_CTR_SMS_RP_ERR_OTHER] = 		{"sms:rp_err_other", "Failed MT SMS delivery attempts (other reason)."},
-	[MSC_CTR_CALL_MO_SETUP] = 		{"call:mo_setup", "Received setup requests from a MS to init a MO call."},
-	[MSC_CTR_CALL_MO_CONNECT_ACK] = 		{"call:mo_connect_ack", "Received a connect ack from MS of a MO call. Call is now successful connected up."},
-	[MSC_CTR_CALL_MT_SETUP] = 		{"call:mt_setup", "Sent setup requests to the MS (MT)."},
-	[MSC_CTR_CALL_MT_CONNECT] = 		{"call:mt_connect", "Sent a connect to the MS (MT)."},
-	[MSC_CTR_CALL_ACTIVE] =			{"call:active", "Count total amount of calls that ever reached active state."},
-	[MSC_CTR_CALL_COMPLETE] = 		{"call:complete", "Count total amount of calls which got terminated by disconnect req or ind after reaching active state."},
-	[MSC_CTR_CALL_INCOMPLETE] = 		{"call:incomplete", "Count total amount of call which got terminated by any other reason after reaching active state."},
+	[MSC_CTR_CALL_MO_SETUP] = 		{"call:mo_setup", "Received MO SETUP messages (MO call establishment)."},
+	[MSC_CTR_CALL_MO_CONNECT_ACK] = 	{"call:mo_connect_ack", "Received MO CONNECT messages (MO call establishment)."},
+	[MSC_CTR_CALL_MT_SETUP] = 		{"call:mt_setup", "Sent MT SETUP messages (MT call establishment)."},
+	[MSC_CTR_CALL_MT_CONNECT] = 		{"call:mt_connect", "Sent MT CONNECT messages (MT call establishment)."},
+	[MSC_CTR_CALL_ACTIVE] =			{"call:active", "Calls that ever reached the active state."},
+	[MSC_CTR_CALL_COMPLETE] = 		{"call:complete", "Calls terminated by DISCONNECT message after reaching the active state."},
+	[MSC_CTR_CALL_INCOMPLETE] = 		{"call:incomplete", "Calls terminated by any other reason after reaching the active state."},
 	[MSC_CTR_NC_SS_MO_REQUESTS] = 		{"nc_ss:mo_requests", "Received MS-initiated call independent SS/USSD requests."},
 	[MSC_CTR_NC_SS_MO_ESTABLISHED] = 	{"nc_ss:mo_established", "Established MS-initiated call independent SS/USSD sessions."},
 	[MSC_CTR_NC_SS_MT_REQUESTS] = 		{"nc_ss:mt_requests", "Received network-initiated call independent SS/USSD requests."},