Remove unnecessary typing import. (#16777)

Summary:
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16777

Differential Revision: D13969679

Pulled By: ezyang

fbshipit-source-id: d4728797a5927ae32628621c654eadb93c0e7682
diff --git a/torch/functional.py b/torch/functional.py
index c47a30c..3cf12a2 100644
--- a/torch/functional.py
+++ b/torch/functional.py
@@ -8,7 +8,6 @@
 from torch._utils import annotate
 from itertools import product
 import math
-from typing import Optional, Tuple, List, Union
 import warnings
 
 __all__ = [