perf/smmuv3: Use msi_get_virq()

Let the core code fiddle with the MSI descriptor retrieval.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211210221815.029143589@linutronix.de

drivers/perf/arm_smmuv3_pmu.c

@@ -684,7 +684,6 @@ static void smmu_pmu_write_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
 
 static void smmu_pmu_setup_msi(struct smmu_pmu *pmu)
 {
-	struct msi_desc *desc;
 	struct device *dev = pmu->dev;
 	int ret;
 
@@ -701,9 +700,7 @@ static void smmu_pmu_setup_msi(struct smmu_pmu *pmu)
 		return;
 	}
 
-	desc = first_msi_entry(dev);
-	if (desc)
-		pmu->irq = desc->irq;
+	pmu->irq = msi_get_virq(dev, 0);
 
 	/* Add callback to free MSIs on teardown */
 	devm_add_action(dev, smmu_pmu_free_msis, dev);