force fully strict read of journal file again

I was thinking that discardIncompleteAppend would make it strict, since
it looks at the end of the bytestring. But, it's applied lazily..

This probably fixes windows, which was failing:

      git-annex.exe: .git\annex\journal\trust.log: DeleteFile "\\\\?\\C:\\Users\\runneradmin\\.t\\5\\tmprepo22\\.git\\annex\\journal\\trust.log": permission denied (The process cannot access the file because it is being used by another process.)

Annex/Journal.hs

@@ -196,8 +196,8 @@ getJournalFileStale (GetPrivate getprivate) file = do
   where
 	jfile = journalFile file
 	getfrom d = catchMaybeIO $
-		discardIncompleteAppend 
-			<$> L.readFile (fromRawFilePath (d P.</> jfile))
+		discardIncompleteAppend . L.fromStrict
+			<$> B.readFile (fromRawFilePath (d P.</> jfile))
 
 -- Note that this forces read of the whole lazy bytestring.
 discardIncompleteAppend :: L.ByteString -> L.ByteString