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: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 3ab80e9..f057730 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2007,7 +2007,7 @@
 			goto done;
 		if (ret) {
 			ret = 0;
-			goto done;
+			break;
 		}
 
 		l = path->nodes[0];
@@ -2015,7 +2015,7 @@
 		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);