lguest: fix timer interrupt setup

Without an IRQ chip set, we now get a WARN_ON and no timer interrupt.  This
prevents booting.

Fortunately, the fix is a one-liner: set up the timer IRQ like everything
else.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 arch/x86/lguest/boot.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -995,6 +995,7 @@ static void lguest_time_irq(unsigned int
 static void lguest_time_init(void)
 {
 	/* Set up the timer interrupt (0) to go to our simple timer routine */
+	lguest_setup_irq(0);
 	irq_set_handler(0, lguest_time_irq);
 
 	clocksource_register(&lguest_clock);