scsi: core: check for device state in __scsi_remove_target()

As it turned out device_get() doesn't use kref_get_unless_zero(), so we
will be always getting a device pointer.  Consequently, we need to check
for the device state in __scsi_remove_target() to avoid tripping over
deleted objects.

Fixes: fbce4d97fd43 ("scsi: fixup kernel warning during rmmod()")
Reported-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_sysfs.c

@@ -1415,7 +1415,10 @@ static void __scsi_remove_target(struct scsi_target *starget)
 		 * check.
 		 */
 		if (sdev->channel != starget->channel ||
-		    sdev->id != starget->id ||
+		    sdev->id != starget->id)
+			continue;
+		if (sdev->sdev_state == SDEV_DEL ||
+		    sdev->sdev_state == SDEV_CANCEL ||
 		    !get_device(&sdev->sdev_gendev))
 			continue;
 		spin_unlock_irqrestore(shost->host_lock, flags);