initctl: let -f force-skip check for built-in service

When calling `initctl -b create` from a start script at bootstrap you
risk blocking the boot since Finit currently cannot reply to IPC during
that period.

This patch allows -f to override this builtin check for the following
initctl commands:

 - touch
 - show
 - edit
 - create
 - delete

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/serv.c

@@ -41,6 +41,10 @@ static int is_builtin(char *arg)
 {
 	svc_t *svc;
 
+	/* skip check, we may be in non-responsive bootstrap */
+	if (iforce)
+		return 0;
+
 	svc = client_svc_find(arg);
 	if (!svc)
 		return 0;