nvme-multipath: put module reference when delayed removal work is canceled

The delayed disk removal work is canceled when a NS (re)appears. However,
we do not put the module reference grabbed in nvme_mpath_remove_disk(), so
fix that.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Author: johnpgarry

drivers/nvme/host/core.c

@@ -4083,7 +4083,8 @@ static int nvme_init_ns_head(struct nvme_ns *ns, struct nvme_ns_info *info)
 	mutex_unlock(&ctrl->subsys->lock);
 
 #ifdef CONFIG_NVME_MULTIPATH
-	cancel_delayed_work(&head->remove_work);
+	if (cancel_delayed_work(&head->remove_work))
+		module_put(THIS_MODULE);
 #endif
 	return 0;