unify batch mode with non-batch by using AnnexedFileSeeker

Command/Add.hs

@@ -80,7 +80,7 @@ seek o = startConcurrency commandStages $ do
 		Batch fmt
 			| updateOnly o ->
 				giveup "--update --batch is not supported"
-			| otherwise -> batchFilesMatching fmt (gofile . toRawFilePath)
+			| otherwise -> batchFilesMatching fmt gofile
 		NoBatch -> do
 			-- Avoid git ls-files complaining about files that
 			-- are not known to git yet, since this will add