s390/irq: Use irq_desc_kstat_cpu() in show_msi_interrupt()

The irq descriptor is already there, no need to look it up again.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20201210194043.769108348@linutronix.de

arch/s390/kernel/irq.c

@@ -124,7 +124,7 @@ static void show_msi_interrupt(struct seq_file *p, int irq)
 	raw_spin_lock_irqsave(&desc->lock, flags);
 	seq_printf(p, "%3d: ", irq);
 	for_each_online_cpu(cpu)
-		seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
+		seq_printf(p, "%10u ", irq_desc_kstat_cpu(desc, cpu));
 
 	if (desc->irq_data.chip)
 		seq_printf(p, " %8s", desc->irq_data.chip->name);