paride/pcd: need to set queue to NULL before put_disk

In pcd_init_units, if blk_mq_init_sq_queue fails, need to set queue to
NULL before put_disk, otherwise null-ptr-deref Read will occur.

put_disk
  kobject_put
    disk_release
      blk_put_queue(disk->queue)

Fixes: f0d1762 ("paride/pcd: Fix potential NULL pointer dereference and mem leak")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: zhengbin <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

drivers/block/paride/pcd.c

@@ -314,8 +314,8 @@ static void pcd_init_units(void)
 		disk->queue = blk_mq_init_sq_queue(&cd->tag_set, &pcd_mq_ops,
 						   1, BLK_MQ_F_SHOULD_MERGE);
 		if (IS_ERR(disk->queue)) {
-			put_disk(disk);
 			disk->queue = NULL;
+			put_disk(disk);
 			continue;
 		}