coresight: etm4x: Make etm4_remove_dev() return void

etm4_remove_dev() returned zero unconditionally. Make it return void
instead, which makes it clear in the callers that there is no error to
handle. Simplify etm4_remove_platform_dev() accordingly.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230518201629.260672-1-u.kleine-koenig@pengutronix.de

drivers/hwtracing/coresight/coresight-etm4x-core.c

@@ -2190,7 +2190,7 @@ static void clear_etmdrvdata(void *info)
 	per_cpu(delayed_probe, cpu) = NULL;
 }
 
-static int __exit etm4_remove_dev(struct etmv4_drvdata *drvdata)
+static void __exit etm4_remove_dev(struct etmv4_drvdata *drvdata)
 {
 	bool had_delayed_probe;
 	/*
@@ -2217,8 +2217,6 @@ static int __exit etm4_remove_dev(struct etmv4_drvdata *drvdata)
 		cscfg_unregister_csdev(drvdata->csdev);
 		coresight_unregister(drvdata->csdev);
 	}
-
-	return 0;
 }
 
 static void __exit etm4_remove_amba(struct amba_device *adev)
@@ -2231,13 +2229,12 @@ static void __exit etm4_remove_amba(struct amba_device *adev)
 
 static int __exit etm4_remove_platform_dev(struct platform_device *pdev)
 {
-	int ret = 0;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(&pdev->dev);
 
 	if (drvdata)
-		ret = etm4_remove_dev(drvdata);
+		etm4_remove_dev(drvdata);
 	pm_runtime_disable(&pdev->dev);
-	return ret;
+	return 0;
 }
 
 static const struct amba_id etm4_ids[] = {