perf/arm_dmc620: Fix hotplug callback leak in dmc620_pmu_init()

dmc620_pmu_init() won't remove the callback added by
cpuhp_setup_state_multi() when platform_driver_register() failed. Remove
the callback by cpuhp_remove_multi_state() in fail path.

Similar to the handling of arm_ccn_init() in commit 26242b33 ("bus:
arm-ccn: Prevent hotplug callback leak")

Fixes: 53c218da ("driver/perf: Add PMU driver for the ARM DMC-620 memory controller")
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Reviewed-by: Punit Agrawal <punit.agrawal@bytedance.com>
Link: https://lore.kernel.org/r/20221115115540.6245-2-shangxiaojing@huawei.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/perf/arm_dmc620_pmu.c

@@ -725,6 +725,8 @@ static struct platform_driver dmc620_pmu_driver = {
 
 static int __init dmc620_pmu_init(void)
 {
+	int ret;
+
 	cpuhp_state_num = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
 				      DMC620_DRVNAME,
 				      NULL,
@@ -732,7 +734,11 @@ static int __init dmc620_pmu_init(void)
 	if (cpuhp_state_num < 0)
 		return cpuhp_state_num;
 
-	return platform_driver_register(&dmc620_pmu_driver);
+	ret = platform_driver_register(&dmc620_pmu_driver);
+	if (ret)
+		cpuhp_remove_multi_state(cpuhp_state_num);
+
+	return ret;
 }
 
 static void __exit dmc620_pmu_exit(void)