btrfs: using btrfs_stack_device_id() get devid

We can use btrfs_stack_device_id() to get dev_item->devid
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/volumes.c

@@ -599,7 +599,7 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 			goto error_close;
 
 		disk_super = (struct btrfs_super_block *)bh->b_data;
-		devid = le64_to_cpu(disk_super->dev_item.devid);
+		devid = btrfs_stack_device_id(&disk_super->dev_item);
 		if (devid != device->devid)
 			goto error_brelse;
 
@@ -701,7 +701,7 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 		goto error_close;
 	}
 	disk_super = (struct btrfs_super_block *)bh->b_data;
-	devid = le64_to_cpu(disk_super->dev_item.devid);
+	devid = btrfs_stack_device_id(&disk_super->dev_item);
 	transid = btrfs_super_generation(disk_super);
 	if (disk_super->label[0])
 		printk(KERN_INFO "device label %s ", disk_super->label);
@@ -1194,7 +1194,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 			goto error_close;
 		}
 		disk_super = (struct btrfs_super_block *)bh->b_data;
-		devid = le64_to_cpu(disk_super->dev_item.devid);
+		devid = btrfs_stack_device_id(&disk_super->dev_item);
 		dev_uuid = disk_super->dev_item.uuid;
 		device = btrfs_find_device(root, devid, dev_uuid,
 					   disk_super->fsid);