libmsc/sgs_iface.c: register sgs_vlr_reset_fsm on DSO load

Change-Id: I80cd2e5645d6e391080376250c0853a3f3f821ef
diff --git a/src/libmsc/sgs_iface.c b/src/libmsc/sgs_iface.c
index f2e74cb..95b68f8 100644
--- a/src/libmsc/sgs_iface.c
+++ b/src/libmsc/sgs_iface.c
@@ -1258,8 +1258,12 @@
 		return NULL;
 	g_sgs = sgs;
 
-	osmo_fsm_register(&sgs_vlr_reset_fsm);
 	sgs_server_open(sgs);
 
 	return sgs;
 }
+
+static __attribute__((constructor)) void on_dso_load(void)
+{
+	OSMO_ASSERT(osmo_fsm_register(&sgs_vlr_reset_fsm) == 0);
+}