powerpc: Use proper accessors for IRQ_* flags

Use the proper accessors instead of open access to irq_desc.
Converted with coccinelle.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/powerpc/sysdev/tsi108_pci.c b/arch/powerpc/sysdev/tsi108_pci.c
index 02c91db..088413a 100644
--- a/arch/powerpc/sysdev/tsi108_pci.c
+++ b/arch/powerpc/sysdev/tsi108_pci.c
@@ -391,7 +391,7 @@
 	DBG("%s(%d, 0x%lx)\n", __func__, virq, hw);
 	if ((virq >= 1) && (virq <= 4)){
 		irq = virq + IRQ_PCI_INTAD_BASE - 1;
-		irq_to_desc(irq)->status |= IRQ_LEVEL;
+		irq_set_status_flags(irq, IRQ_LEVEL);
 		set_irq_chip(irq, &tsi108_pci_irq);
 	}
 	return 0;