server: Add an open_file() function to the object operations.
diff --git a/server/snapshot.c b/server/snapshot.c
index fafe65c..14ec97b 100644
--- a/server/snapshot.c
+++ b/server/snapshot.c
@@ -69,6 +69,7 @@
     no_get_fd,                    /* get_fd */
     no_map_access,                /* map_access */
     no_lookup_name,               /* lookup_name */
+    no_open_file,                 /* open_file */
     no_close_handle,              /* close_handle */
     snapshot_destroy              /* destroy */
 };