mini-os: drop shutdown variables when CONFIG_XENBUS=n

Shutdown variables are meaningless when CONFIG_XENBUS=n since no
shutdown event will ever happen.  Better make sure that no code tries
to use it and never get the hoped shutdown event.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Committed-by: Keir Fraser <keir@xen.org>

extras/mini-os/kernel.c

@@ -48,9 +48,11 @@
 
 uint8_t xen_features[XENFEAT_NR_SUBMAPS * 32];
 
+#ifdef CONFIG_XENBUS
 unsigned int do_shutdown = 0;
 unsigned int shutdown_reason;
 DECLARE_WAIT_QUEUE_HEAD(shutdown_queue);
+#endif
 
 void setup_xen_features(void)
 {