Merge branch 'issue-231'

This branch hopefully addresses

	https://github.com/git-for-windows/git/issues/231

where `git repack` could not delete the object directory because there
was still an open handle on it.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

sha1_file.c

@@ -3507,12 +3507,12 @@ static int for_each_file_in_obj_subdir(int subdir_nr,
 				break;
 		}
 	}
-	strbuf_setlen(path, baselen);
+	closedir(dir);
 
+	strbuf_setlen(path, baselen);
 	if (!r && subdir_cb)
 		r = subdir_cb(subdir_nr, path->buf, data);
 
-	closedir(dir);
 	return r;
 }