[PATCH 08 of 11] vfs: fix two setattr calls to use sysstrs

[Augie Fackler]

# HG changeset patch
# User Augie Fackler <raf at durin42.com>
# Date 1490567343 14400
#      Sun Mar 26 18:29:03 2017 -0400
# Node ID 8d683b05a16a94321d6c891ddc40f1bc3976db64
# Parent  e7fe3ab60132647a9c3b86b2960b385e61b9dcf0
vfs: fix two setattr calls to use sysstrs

diff --git a/mercurial/vfs.py b/mercurial/vfs.py
--- a/mercurial/vfs.py
+++ b/mercurial/vfs.py
@@ -480,7 +480,7 @@ class closewrapbase(object):
     Do not instantiate outside of the vfs layer.
     """
     def __init__(self, fh):
-        object.__setattr__(self, '_origfh', fh)
+        object.__setattr__(self, pycompat.sysstr('_origfh'), fh)
 
     def __getattr__(self, attr):
         return getattr(self._origfh, attr)
@@ -618,7 +618,8 @@ class checkambigatclosing(closewrapbase)
     """
     def __init__(self, fh):
         super(checkambigatclosing, self).__init__(fh)
-        object.__setattr__(self, '_oldstat', util.filestat(fh.name))
+        object.__setattr__(self, pycompat.sysstr('_oldstat'),
+                           util.filestat(fh.name))
 
     def _checkambig(self):
         oldstat = self._oldstat