gprs_ns: Use gprs_ns_tx_alive() instead of gprs_ns_tx_simple()

If we use gprs_ns_tx_alive() we will get logging for free.

Change-Id: I53d410d13540d389096c40425e1fa2eb7460b16b
diff --git a/src/gb/gprs_ns.c b/src/gb/gprs_ns.c
index 1281c9f..5c75694 100644
--- a/src/gb/gprs_ns.c
+++ b/src/gb/gprs_ns.c
@@ -960,7 +960,7 @@
 	rc = gprs_ns_tx_reset_ack(*nsvc);
 
 	/* start the test procedure */
-	gprs_ns_tx_simple((*nsvc), NS_PDUT_ALIVE);
+	gprs_ns_tx_alive(*nsvc);
 	nsvc_start_timer((*nsvc), NSVC_TIMER_TNS_TEST);
 
 	return rc;
@@ -1084,7 +1084,7 @@
 		osmo_timer_del(&(*nsvc)->timer);
 	}
 	/* Initiate TEST proc.: Send ALIVE and start timer */
-	rc = gprs_ns_tx_simple(*nsvc, NS_PDUT_ALIVE);
+	rc = gprs_ns_tx_alive(*nsvc);
 	nsvc_start_timer(*nsvc, NSVC_TIMER_TNS_TEST);
 
 	return rc;