perf: arm_dsu: Fix hotplug callback leak in dsu_pmu_init()

dsu_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: 7520fa99 ("perf: ARM DynamIQ Shared Unit PMU support")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20221115070207.32634-2-yuancan@huawei.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/perf/arm_dsu_pmu.c

@@ -858,7 +858,11 @@ static int __init dsu_pmu_init(void)
 	if (ret < 0)
 		return ret;
 	dsu_pmu_cpuhp_state = ret;
-	return platform_driver_register(&dsu_pmu_driver);
+	ret = platform_driver_register(&dsu_pmu_driver);
+	if (ret)
+		cpuhp_remove_multi_state(dsu_pmu_cpuhp_state);
+
+	return ret;
 }
 
 static void __exit dsu_pmu_exit(void)