cosmetic: ssn: some more comments

Change-Id: I87f76ab19d834d96a268b0d47b9dfe2424151d63
diff --git a/src/gb/gprs_ns2_sns.c b/src/gb/gprs_ns2_sns.c
index a82da95..698f60a 100644
--- a/src/gb/gprs_ns2_sns.c
+++ b/src/gb/gprs_ns2_sns.c
@@ -79,10 +79,10 @@
 	GPRS_SNS_EV_RX_ADD,
 	GPRS_SNS_EV_RX_DELETE,
 	GPRS_SNS_EV_RX_CHANGE_WEIGHT,
-	GPRS_SNS_EV_REQ_NO_NSVC,
+	GPRS_SNS_EV_REQ_NO_NSVC,		/*!< no more NS-VC remaining (all dead) */
 	GPRS_SNS_EV_REQ_NSVC_ALIVE,		/*!< a NS-VC became alive */
-	GPRS_SNS_EV_REQ_ADD_BIND,
-	GPRS_SNS_EV_REQ_DELETE_BIND,
+	GPRS_SNS_EV_REQ_ADD_BIND,		/*!< add a new local bind to this NSE */
+	GPRS_SNS_EV_REQ_DELETE_BIND,		/*!< remove a local bind from this NSE */
 };
 
 static const struct value_string gprs_sns_event_names[] = {