pmdomain: qcom: rpmhpd: Simplify locking with guard()

Simplify error handling (less gotos) over locks with guard().
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konradybcio@kernel.org>
Link: https://lore.kernel.org/r/20240823-cleanup-h-guard-pm-domain-v1-7-8320722eaf39@linaro.orgSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/pmdomain/qcom/rpmhpd.c

 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (c) 2018, The Linux Foundation. All rights reserved.*/
 
+#include <linux/cleanup.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
@@ -775,9 +776,9 @@ static int rpmhpd_set_performance_state(struct generic_pm_domain *domain,
 					unsigned int level)
 {
 	struct rpmhpd *pd = domain_to_rpmhpd(domain);
-	int ret = 0, i;
+	int ret, i;
 
-	mutex_lock(&rpmhpd_lock);
+	guard(mutex)(&rpmhpd_lock);
 
 	for (i = 0; i < pd->level_count; i++)
 		if (level <= pd->level[i])
@@ -797,14 +798,12 @@ static int rpmhpd_set_performance_state(struct generic_pm_domain *domain,
 
 		ret = rpmhpd_aggregate_corner(pd, i);
 		if (ret)
-			goto out;
+			return ret;
 	}
 
 	pd->corner = i;
-out:
-	mutex_unlock(&rpmhpd_lock);
 
-	return ret;
+	return 0;
 }
 
 static int rpmhpd_update_level_mapping(struct rpmhpd *rpmhpd)