ns2: Fix argv index in logging filter VTY commands

Change-Id: I8adaf8094ef028b2d580e918532d6712d2ebbc2c
Related: SYS#5232
diff --git a/src/gb/gprs_ns2_vty.c b/src/gb/gprs_ns2_vty.c
index 9c214a3..43e9c2c 100644
--- a/src/gb/gprs_ns2_vty.c
+++ b/src/gb/gprs_ns2_vty.c
@@ -778,7 +778,7 @@
 {
 	struct log_target *tgt;
 	struct gprs_ns2_nse *nse;
-	uint16_t id = atoi(argv[1]);
+	uint16_t id = atoi(argv[0]);
 
 	log_tgt_mutex_lock();
 	tgt = osmo_log_vty2tgt(vty);
@@ -810,7 +810,7 @@
 {
 	struct log_target *tgt;
 	struct gprs_ns2_vc *nsvc;
-	uint16_t id = atoi(argv[1]);
+	uint16_t id = atoi(argv[0]);
 
 	log_tgt_mutex_lock();
 	tgt = osmo_log_vty2tgt(vty);