gprs_ns2_sns: Dispatch inbound SNS-ACK to FSM

We don't really handle inbound SNS-ACK yet (as we don't originate
SNS ADD/DEL/CHGWEIGHT procedures yet).  However, the message
receive code should already dispatch those events to the FSM,
just like we do for the (equally unimplemented) handling of inbound
SNS-SIZE which is already dispatched to the FSM.

Change-Id: If6d5f96d85e6f05534fe49376f4473d912535ad4
diff --git a/src/gb/gprs_ns2_sns.c b/src/gb/gprs_ns2_sns.c
index 698f60a..0bb7422 100644
--- a/src/gb/gprs_ns2_sns.c
+++ b/src/gb/gprs_ns2_sns.c
@@ -79,6 +79,7 @@
 	GPRS_SNS_EV_RX_ADD,
 	GPRS_SNS_EV_RX_DELETE,
 	GPRS_SNS_EV_RX_CHANGE_WEIGHT,
+	GPRS_SNS_EV_RX_ACK,			/*!< Rx of SNS-ACK (response to ADD/DELETE/CHG_WEIGHT */
 	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,		/*!< add a new local bind to this NSE */
@@ -94,6 +95,7 @@
 	{ GPRS_SNS_EV_RX_CONFIG_ACK,		"RX_CONFIG_ACK" },
 	{ GPRS_SNS_EV_RX_ADD,	    		"RX_ADD" },
 	{ GPRS_SNS_EV_RX_DELETE,		"RX_DELETE" },
+	{ GPRS_SNS_EV_RX_ACK,			"RX_ACK" },
 	{ GPRS_SNS_EV_RX_CHANGE_WEIGHT,		"RX_CHANGE_WEIGHT" },
 	{ GPRS_SNS_EV_REQ_NO_NSVC,		"REQ_NO_NSVC" },
 	{ GPRS_SNS_EV_REQ_NSVC_ALIVE,		"REQ_NSVC_ALIVE"},
@@ -1599,8 +1601,7 @@
 		osmo_fsm_inst_dispatch(fi, GPRS_SNS_EV_RX_CHANGE_WEIGHT, tp);
 		break;
 	case SNS_PDUT_ACK:
-		LOGPFSML(fi, LOGL_NOTICE, "NSEI=%u Rx unsupported SNS PDU type %s\n", nsei,
-			 get_value_string(gprs_ns_pdu_strings, nsh->pdu_type));
+		osmo_fsm_inst_dispatch(fi, GPRS_SNS_EV_RX_ACK, tp);
 		break;
 	default:
 		LOGPFSML(fi, LOGL_ERROR, "NSEI=%u Rx unknown SNS PDU type %s\n", nsei,