arm64: perf: fix unassigned cpu_pmu->plat_device when probing PMU PPIs

Commit d795ef9a ("arm64: perf: don't warn about missing
interrupt-affinity property for PPIs") added a check for PPIs so that
we avoid parsing the interrupt-affinity property for these naturally
affine interrupts.

Unfortunately, this check can trigger an early (successful) return and
we will not assign the value of cpu_pmu->plat_device. This patch fixes
the issue.
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm64/kernel/perf_event.c

@@ -1318,7 +1318,7 @@ static int armpmu_device_probe(struct platform_device *pdev)
 	/* Don't bother with PPIs; they're already affine */
 	irq = platform_get_irq(pdev, 0);
 	if (irq >= 0 && irq_is_percpu(irq))
-		return 0;
+		goto out;
 
 	irqs = kcalloc(pdev->num_resources, sizeof(*irqs), GFP_KERNEL);
 	if (!irqs)
@@ -1356,6 +1356,7 @@ static int armpmu_device_probe(struct platform_device *pdev)
 	else
 		kfree(irqs);
 
+out:
 	cpu_pmu->plat_device = pdev;
 	return 0;
 }