genirq: Remove unused extern declaration

commit 3795de23 ("genirq: Distangle kernel/irq/handle.c")
left behind this.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230720143625.29176-1-yuehaibing@huawei.com

kernel/irq/internals.h

@@ -108,8 +108,6 @@ extern int __irq_get_irqchip_state(struct irq_data *data,
 				   enum irqchip_irq_state which,
 				   bool *state);
 
-extern void init_kstat_irqs(struct irq_desc *desc, int node, int nr);
-
 irqreturn_t __handle_irq_event_percpu(struct irq_desc *desc);
 irqreturn_t handle_irq_event_percpu(struct irq_desc *desc);
 irqreturn_t handle_irq_event(struct irq_desc *desc);