gprs_ns2: fix comment of alive NS-VC

There is no active NS-VCs only alive or dead.

Change-Id: Idb5d2ae4a99a472e38601ff841b8046ecf89d1bc
diff --git a/src/gb/gprs_ns2_internal.h b/src/gb/gprs_ns2_internal.h
index 88e352a..d4764f6 100644
--- a/src/gb/gprs_ns2_internal.h
+++ b/src/gb/gprs_ns2_internal.h
@@ -174,10 +174,10 @@
 
 	struct osmo_fsm_inst *bss_sns_fi;
 
-	/*! sum of all the data weight of _active_ NS-VCs */
+	/*! sum of all the data weight of _alive_ NS-VCs */
 	uint32_t sum_data_weight;
 
-	/*! sum of all the signalling weight of _active_ NS-VCs */
+	/*! sum of all the signalling weight of _alive_ NS-VCs */
 	uint32_t sum_sig_weight;
 };