drivers/perf: arm_spe_pmu: Fix some coding style issues

Fix some coding style issues reported by checkpatch.pl, including
following types:

WARNING: void function return statements are not generally useful
WARNING: Possible unnecessary 'out of memory' message

Signed-off-by: Junhao He <hejunhao2@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620736054-58412-2-git-send-email-f.fangjian@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

drivers/perf/arm_spe_pmu.c

@@ -1044,7 +1044,6 @@ static void __arm_spe_pmu_dev_probe(void *info)
 		 spe_pmu->max_record_sz, spe_pmu->align, spe_pmu->features);
 
 	spe_pmu->features |= SPE_PMU_FEAT_DEV_PROBED;
-	return;
 }
 
 static void __arm_spe_pmu_reset_local(void)
@@ -1190,10 +1189,8 @@ static int arm_spe_pmu_device_probe(struct platform_device *pdev)
 	}
 
 	spe_pmu = devm_kzalloc(dev, sizeof(*spe_pmu), GFP_KERNEL);
-	if (!spe_pmu) {
-		dev_err(dev, "failed to allocate spe_pmu\n");
+	if (!spe_pmu)
 		return -ENOMEM;
-	}
 
 	spe_pmu->handle = alloc_percpu(typeof(*spe_pmu->handle));
 	if (!spe_pmu->handle)