Revert D27960766: ns for fx: additional bugfix for user defined functions
Test Plan: revert-hammer
Differential Revision:
D27960766 (https://github.com/pytorch/pytorch/commit/9bd14da6e4f140451e3b116171f6ec287f398951)
Original commit changeset: 02935d2f400a
fbshipit-source-id: e7026c8637a591b6ffef288da8ef6306cdb9eb95
