cxl/pci: Remove unnecessary device reference management in sanitize work

Given that any particular put_device() could be the final put of the
device, the fact that there are usages of cxlds->dev after
put_device(cxlds->dev) is a red flag. Drop the reference counting since
the device is pinned by being registered and will not be unregistered
without triggering the driver + workqueue to shutdown.
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/pci.c

@@ -152,8 +152,6 @@ static void cxl_mbox_sanitize_work(struct work_struct *work)
 	mutex_lock(&mds->mbox_mutex);
 	if (cxl_mbox_background_complete(cxlds)) {
 		mds->security.poll_tmo_secs = 0;
-		put_device(cxlds->dev);
-
 		if (mds->security.sanitize_node)
 			sysfs_notify_dirent(mds->security.sanitize_node);
 
@@ -296,9 +294,6 @@ static int __cxl_pci_mbox_send_cmd(struct cxl_memdev_state *mds,
 		 */
 		if (mbox_cmd->opcode == CXL_MBOX_OP_SANITIZE) {
 			if (mds->security.poll) {
-				/* hold the device throughout */
-				get_device(cxlds->dev);
-
 				/* give first timeout a second */
 				timeout = 1;
 				mds->security.poll_tmo_secs = timeout;