Ensure we do not hand out the dskbuddy before it is safe to

src/fellow_log.c

@@ -6141,6 +6141,7 @@ fellow_log_set_diag(struct fellow_fd *ffd, fellow_log_diag_f *diag)
 buddy_t *
 fellow_dskbuddy(struct fellow_fd *ffd)
 {
+	fellow_wait_open(ffd);
 	return (ffd->dskbuddy);
 }