Fix a couple of ssize-t issues reported by Alexander Belopolsky on python-dev

Modules/mmapmodule.c

@@ -470,7 +470,7 @@ static PyObject *
 mmap_tell_method(mmap_object *self, PyObject *unused)
 {
 	CHECK_VALID(NULL);
-	return PyInt_FromLong((long) self->pos);
+	return PyInt_FromSsize_t(self->pos);
 }
 
 static PyObject *

Objects/fileobject.c

@@ -922,7 +922,7 @@ file_readinto(PyFileObject *f, PyObject *args)
 		ndone += nnow;
 		ntodo -= nnow;
 	}
-	return PyInt_FromLong((long)ndone);
+	return PyInt_FromSsize_t(ndone);
 }
 
 /**************************************************************************