pci: pcie-designware: Remove irq_desc abuse

There is no reason to care about irq_desc in that context, escpecially
as irq_data for that interrupt is retrieved as well.

Use the proper accessor for the msi descriptor

Signed-off-by: Thomas Gleixner <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Acked-by: Bjorn Helgaas <[e-mail]>
Acked-by: Jingoo Han <[e-mail]>
Cc: Mohit Kumar <[e-mail]>
Cc: pci <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Thomas Gleixner <[e-mail]>

drivers/pci/host/pcie-designware.c

···
 static void clear_irq(unsigned int irq)
 {
 	unsigned int pos, nvec;
-	struct irq_desc *desc;
 	struct msi_desc *msi;
 	struct pcie_port *pp;
 	struct irq_data *data = irq_get_irq_data(irq);
 
 	/* get the port structure */
-	desc = irq_to_desc(irq);
-	msi = irq_desc_get_msi_desc(desc);
+	msi = irq_data_get_msi(data);
 	pp = sys_to_pcie(msi->dev->bus->sysdata);
 	if (!pp) {
 		BUG();