Update src/attr/_make.py

Co-authored-by: Paul Ganssle <paul@ganssle.io>

src/attr/_make.py

@@ -674,7 +674,7 @@ def _create_slots_class(self):
         # __setattr__, that needs to be reset.
         # XXX: This can be confused by subclassing a slotted attrs class with
         # XXX: a non-attrs class and subclass the resulting class with an attrs
-        # XXX: class.  See `test_slotted_confused for details.  For now that's
+        # XXX: class.  See `test_slotted_confused` for details.  For now that's
         # XXX: OK with us.
         if not self._has_own_setattr:
             # There's metaclass magic that may result in a baseclass without