Btrfs: properly update space information after shrinking device.

Change 'goto done' to 'break' for the case of all device extents have
been freed, so that the code updates space information will be execute.
Signed-off-by: NYan Zheng <zheng.yan@oracle.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

fs/btrfs/volumes.c

@@ -2007,7 +2007,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 			goto done;
 		if (ret) {
 			ret = 0;
-			goto done;
+			break;
 		}
 
 		l = path->nodes[0];
@@ -2015,7 +2015,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 		btrfs_item_key_to_cpu(l, &key, path->slots[0]);
 
 		if (key.objectid != device->devid)
-			goto done;
+			break;
 
 		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
 		length = btrfs_dev_extent_length(l, dev_extent);