nvme: fix memory leak for power latency tolerance

Unconditionally hide device pm latency tolerance when uninitializing
the controller to ensure all qos resources are released so that we're
not leaking this memory. This is safe to call if none were allocated in
the first place, or were previously freed.

Fixes: c5552fde("nvme: Enable autonomous power state transitions")
Suggested-by: Keith Busch <keith.busch@intel.com>
Tested-by: David Milburn <dmilburn@redhat.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
[changelog]
Signed-off-by: Keith Busch <keith.busch@intel.com>