nvme: forward port sysfs delete fix

We had a late fix that modified nvme_sysfs_delete() after the staging
branch for the next merge window relocated the function to a new file.
Port commit 2eb94dd ("nvme: do not let the user delete a ctrl
before a complete") to the latest to avoid a potentially confusing merge
conflict.

Cc: Maurizio Lombardi <mlombard@redhat.com>
Cc: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Author: keithbusch

drivers/nvme/host/sysfs.c

@@ -202,6 +202,9 @@ static ssize_t nvme_sysfs_delete(struct device *dev,
 {
 	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
 
+	if (!test_bit(NVME_CTRL_STARTED_ONCE, &ctrl->flags))
+		return -EBUSY;
+
 	if (device_remove_file_self(dev, attr))
 		nvme_delete_ctrl_sync(ctrl);
 	return count;