mips: Fix i8253 clockevent fallout

pit_clockevent wants to replaced in the argument of the callback
function as well.

Reported-by; Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/mips/kernel/i8253.c

@@ -12,7 +12,7 @@
 
 static irqreturn_t timer_interrupt(int irq, void *dev_id)
 {
-	i8253_clockevent.event_handler(&pit_clockevent);
+	i8253_clockevent.event_handler(&i8253_clockevent);
 
 	return IRQ_HANDLED;
 }