perf/smmuv3: Remove the leftover put_cpu() in error path

[ Upstream commit 8ae4bcf4 ]

In smmu_pmu_probe(), there is put_cpu() in the error path,
which is wrong because we use raw_smp_processor_id() to
get the cpu ID, not get_cpu(), remove it.

While we are at it, kill 'out_cpuhp_err' altogether and
just return err if we fail to add the hotplug instance.

Acked-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>