LoongArch: Switch to irq_set_nr_irqs()

Use the irq_set_nr_irqs() function instead of the global variable
'nr_irqs'. Prepare for changing 'nr_irqs' from an exported global
variable into a variable with file scope.

Signed-off-by: Bart Van Assche <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: https://lore.kernel.org/all/[email protected]

Author: bvanassche

arch/loongarch/kernel/irq.c

@@ -92,9 +92,9 @@ int __init arch_probe_nr_irqs(void)
 	int nr_io_pics = bitmap_weight(loongson_sysconf.cores_io_master, NR_CPUS);
 
 	if (!cpu_has_avecint)
-		nr_irqs = (64 + NR_VECTORS * nr_io_pics);
+		irq_set_nr_irqs(64 + NR_VECTORS * nr_io_pics);
 	else
-		nr_irqs = (64 + NR_VECTORS * (nr_cpu_ids + nr_io_pics));
+		irq_set_nr_irqs(64 + NR_VECTORS * (nr_cpu_ids + nr_io_pics));
 
 	return NR_IRQS_LEGACY;
 }