vty: Change the return type from enum to int

clang complained that different enums are mixed with the
return type and we actually want this to be an int now.
diff --git a/openbsc/src/osmo-bsc/osmo_bsc_main.c b/openbsc/src/osmo-bsc/osmo_bsc_main.c
index ee86cb6..3ab1267 100644
--- a/openbsc/src/osmo-bsc/osmo_bsc_main.c
+++ b/openbsc/src/osmo-bsc/osmo_bsc_main.c
@@ -142,7 +142,7 @@
 	}
 }
 
-extern enum node_type bsc_vty_go_parent(struct vty *vty);
+extern int bsc_vty_go_parent(struct vty *vty);
 
 static struct vty_app_info vty_info = {
 	.name 		= "OsmoBSC",