genirq: Remove export of kstat_irqs_cpu

The statistics accessor is only used by proc/stats and
show_interrupts(). Both are compiled in.

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

kernel/irq/irqdesc.c

@@ -257,4 +257,3 @@ unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
 	struct irq_desc *desc = irq_to_desc(irq);
 	return desc ? desc->kstat_irqs[cpu] : 0;
 }
-EXPORT_SYMBOL(kstat_irqs_cpu);