nvme-pci: set the errno on ctrl state change error

This patch removes the confusing assignment of the variable result at
the time of declaration and sets the value in error cases next to the
places where the actual error is happening.

Here we also set the result value to -ENODEV when we fail at the final
ctrl state transition in nvme_reset_work(). Without this assignment
result will hold 0 from nvme_setup_io_queue() and on failure 0 will be
passed to he nvme_remove_dead_ctrl() from final state transition.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/pci.c

@@ -2467,11 +2467,13 @@ static void nvme_reset_work(struct work_struct *work)
 	struct nvme_dev *dev =
 		container_of(work, struct nvme_dev, ctrl.reset_work);
 	bool was_suspend = !!(dev->ctrl.ctrl_config & NVME_CC_SHN_NORMAL);
-	int result = -ENODEV;
+	int result;
 	enum nvme_ctrl_state new_state = NVME_CTRL_LIVE;
 
-	if (WARN_ON(dev->ctrl.state != NVME_CTRL_RESETTING))
+	if (WARN_ON(dev->ctrl.state != NVME_CTRL_RESETTING)) {
+		result = -ENODEV;
 		goto out;
+	}
 
 	/*
 	 * If we're called to reset a live controller first shut it down before
@@ -2575,6 +2577,7 @@ static void nvme_reset_work(struct work_struct *work)
 	if (!nvme_change_ctrl_state(&dev->ctrl, new_state)) {
 		dev_warn(dev->ctrl.device,
 			"failed to mark controller state %d\n", new_state);
+		result = -ENODEV;
 		goto out;
 	}