nvme: do not try to reconfigure APST when the controller is not live

Do not call nvme_configure_apst when the controller is not live, given
that nvme_configure_apst will fail due the lack of an admin queue when
the controller is being torn down and nvme_set_latency_tolerance is
called from dev_pm_qos_hide_latency_tolerance.

Fixes: 510a405d("nvme: fix memory leak for power latency tolerance")
Reported-by: Peng Liu <liupeng17@lenovo.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>

drivers/nvme/host/core.c

@@ -2321,6 +2321,7 @@ static void nvme_set_latency_tolerance(struct device *dev, s32 val)
 
 	if (ctrl->ps_max_latency_us != latency) {
 		ctrl->ps_max_latency_us = latency;
+		if (ctrl->state == NVME_CTRL_LIVE)
 			nvme_configure_apst(ctrl);
 	}
 }