Revert "avoid using MissingH's HVFS layer"

This reverts commit 0700fbc477.

This broke unit and test suite cleanup. The difference is that
dirContentsRecursive only returns files, but this needs to also operate on
directories.

Command/Uninit.hs

@@ -18,6 +18,9 @@ import Annex.Content
 import Annex.Init
 import Utility.FileMode
 
+import System.IO.HVFS
+import System.IO.HVFS.Utils
+
 cmd :: [Command]
 cmd = [addCheck check $ command "uninit" paramPaths seek 
 	SectionUtility "de-initialize git-annex and clean out repository"]
@@ -88,7 +91,7 @@ finish = do
  - preparation for removal. -}
 prepareRemoveAnnexDir :: FilePath -> IO ()
 prepareRemoveAnnexDir annexdir =
-	mapM_ (void . tryIO . allowWrite) =<< dirContentsRecursive annexdir
+	recurseDir SystemFS annexdir >>= mapM_ (void . tryIO . allowWrite)
 
 {- Keys that were moved out of the annex have a hard link still in the
  - annex, with > 1 link count, and those can be removed.