hnbgw: use proper talloc ctx for vty telnet init

Change-Id: I355c6e5489f24566612528cd679c5cab21eed008
diff --git a/src/hnbgw.c b/src/hnbgw.c
index 45a753f..ff3e2a9 100644
--- a/src/hnbgw.c
+++ b/src/hnbgw.c
@@ -471,7 +471,7 @@
 		log_set_log_level(osmo_stderr_target,
 				  hnbgw_cmdline_config.log_level);
 
-	rc = telnet_init_dynif(NULL, g_hnb_gw, vty_get_bind_addr(), OSMO_VTY_PORT_HNBGW);
+	rc = telnet_init_dynif(tall_hnb_ctx, g_hnb_gw, vty_get_bind_addr(), OSMO_VTY_PORT_HNBGW);
 	if (rc < 0) {
 		perror("Error binding VTY port");
 		exit(1);