ns2: Send NSVC representation in NS_AFF_CAUSE_VC_* status indication

NS_AFF_CAUSE_VC_* failure and recovery should indicate the NSVC in
question. Use the string representation reported by gprs_ns2_ll_str()
for that.

NS_AFF_CAUSE_VC_RECOVERY was never sent so do that on unblock as well.

Change-Id: Iad6f0dc4565a46868cbbe17c361dcd473006c83d
Related: SYS#4998
diff --git a/src/gb/gprs_ns2_vc_fsm.c b/src/gb/gprs_ns2_vc_fsm.c
index 4fa53c1..0d30f12 100644
--- a/src/gb/gprs_ns2_vc_fsm.c
+++ b/src/gb/gprs_ns2_vc_fsm.c
@@ -318,8 +318,11 @@
 static void gprs_ns2_st_unblocked_on_enter(struct osmo_fsm_inst *fi, uint32_t old_state)
 {
 	struct gprs_ns2_vc_priv *priv = fi->priv;
+	struct gprs_ns2_vc *nsvc = priv->nsvc;
+	struct gprs_ns2_nse *nse = nsvc->nse;
 
-	ns2_nse_notify_unblocked(priv->nsvc, true);
+	ns2_nse_notify_unblocked(nsvc, true);
+	ns2_prim_status_ind(nse, nsvc, 0, NS_AFF_CAUSE_VC_RECOVERY);
 }
 
 static void gprs_ns2_st_unblocked(struct osmo_fsm_inst *fi, uint32_t event, void *data)