ospf6d: improve ordered shutdown

Improve the _disable/_enable infrastructure so it gets into
a more usable shape and make 'no router ospf6' actually work.

Signed-off-by: Christian Franke <chris@opensourcerouting.org>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/ospf6d/ospf6_asbr.h b/ospf6d/ospf6_asbr.h
index 72e4914..73770cc 100644
--- a/ospf6d/ospf6_asbr.h
+++ b/ospf6d/ospf6_asbr.h
@@ -89,6 +89,7 @@
 extern int ospf6_redistribute_config_write (struct vty *vty);
 
 extern void ospf6_asbr_init (void);
+extern void ospf6_asbr_redistribute_reset (void);
 extern void ospf6_asbr_terminate (void);
 
 extern int config_write_ospf6_debug_asbr (struct vty *vty);