sgsn init: pass sgsn_config pointer to sgsn_vty_init(), not sgsn_parse_config

In an upcoming commit, sgsn_vty_init() will require access to the global sgsn
config struct to initialize a generic VTY command with the proper config
destination address, see Change-Id I5b5b6a9678b458affa86800afb1ec726e66eed88.

Change-Id: Ie6b6e5422987586531a898e0c5b867623dbecb0f
diff --git a/src/gprs/sgsn_main.c b/src/gprs/sgsn_main.c
index 41cebef..d871939 100644
--- a/src/gprs/sgsn_main.c
+++ b/src/gprs/sgsn_main.c
@@ -350,7 +350,7 @@
 	vty_init(&vty_info);
 	logging_vty_add_cmds(NULL);
 	osmo_stats_vty_add_cmds(&gprs_log_info);
-	sgsn_vty_init();
+	sgsn_vty_init(&sgsn_inst.cfg);
 	ctrl_vty_init(tall_bsc_ctx);
 #ifdef BUILD_IU
 	iu_vty_init(&asn_debug);
@@ -382,7 +382,7 @@
 	sgsn_cdr_init(&sgsn_inst);
 	/* FIXME: register signal handler for SS_L_NS */
 
-	rc = sgsn_parse_config(sgsn_inst.config_file, &sgsn_inst.cfg);
+	rc = sgsn_parse_config(sgsn_inst.config_file);
 	if (rc < 0) {
 		LOGP(DGPRS, LOGL_FATAL, "Error in config file\n");
 		exit(2);