mn10300: Use the core irq stats function

Let the core do the irq_desc resolution.

No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: mn10300 <linux-am33-list@redhat.com>
Link: http://lkml.kernel.org/r/20140223212737.751487689@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/mn10300/kernel/mn10300-watchdog.c

@@ -142,7 +142,7 @@ void watchdog_interrupt(struct pt_regs *regs, enum exception_code excep)
 	NMICR = NMICR_WDIF;
 
 	nmi_count(smp_processor_id())++;
-	kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
+	kstat_incr_irq_this_cpu(irq);
 
 	for_each_online_cpu(cpu) {