use one talloc context for entire vty code
diff --git a/openbsc/include/vty/vty.h b/openbsc/include/vty/vty.h
index d43d992..ab34cd3 100644
--- a/openbsc/include/vty/vty.h
+++ b/openbsc/include/vty/vty.h
@@ -147,5 +147,5 @@
 int vty_shell_serv (struct vty *);
 void vty_hello (struct vty *);
 
-
+void *tall_vty_ctx;
 #endif