This reverts r63675 based on the discussion in this thread:

 http://mail.python.org/pipermail/python-dev/2008-June/079988.html

Python 2.6 should stick with PyString_* in its codebase.  The PyBytes_* names
in the spirit of 3.0 are available via a #define only.  See the email thread.
diff --git a/Modules/errnomodule.c b/Modules/errnomodule.c
index df2ceff..696d396 100644
--- a/Modules/errnomodule.c
+++ b/Modules/errnomodule.c
@@ -21,7 +21,7 @@
 static void
 _inscode(PyObject *d, PyObject *de, char *name, int code)
 {
-	PyObject *u = PyBytes_FromString(name);
+	PyObject *u = PyString_FromString(name);
 	PyObject *v = PyInt_FromLong((long) code);
 
 	/* Don't bother checking for errors; they'll be caught at the end