PCI/MSI: Use msi_mask_irq() in pci_msi_shutdown()

No point in using the raw write function from shutdown. Preparatory change
to introduce proper serialization for the msi_desc::masked cache.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210729222542.674391354@linutronix.de

drivers/pci/msi.c

@@ -961,7 +961,7 @@ static void pci_msi_shutdown(struct pci_dev *dev)
 
 	/* Return the device with MSI unmasked as initial states */
 	mask = msi_mask(desc->msi_attrib.multi_cap);
-	__pci_msi_desc_mask_irq(desc, mask, 0);
+	msi_mask_irq(desc, mask, 0);
 
 	/* Restore dev->irq to its default pin-assertion IRQ */
 	dev->irq = desc->msi_attrib.default_irq;