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_internal.h b/src/gb/gprs_ns2_internal.h
index b480391..dee3ab7 100644
--- a/src/gb/gprs_ns2_internal.h
+++ b/src/gb/gprs_ns2_internal.h
@@ -221,6 +221,7 @@
 
 void gprs_ns2_sns_dump_vty(struct vty *vty, const struct gprs_ns2_nse *nse, bool stats);
 void ns2_prim_status_ind(struct gprs_ns2_nse *nse,
+			 struct gprs_ns2_vc *nsvc,
 			 uint16_t bvci,
 			 enum gprs_ns2_affecting_cause cause);
 void ns2_nse_notify_alive(struct gprs_ns2_vc *nsvc, bool alive);