Update modules/__init__.pyi.in to include Identity (#29114)
Summary:
Running mypy on the following code is throwing an error, `Module has no attribute Identity`:
```
import torch.nn as nn
layer = nn.Identity()
```
Using the following instead does not give an error:
```
import torch
layer = torch.nn.Identity()
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/29114
Differential Revision: D18298225
Pulled By: soumith
fbshipit-source-id: b271bf00086876cca8d63ae0cde6cebf69a7051e
diff --git a/torch/nn/modules/__init__.pyi.in b/torch/nn/modules/__init__.pyi.in
index d09a99c..d655532 100644
--- a/torch/nn/modules/__init__.pyi.in
+++ b/torch/nn/modules/__init__.pyi.in
@@ -17,7 +17,7 @@
from .fold import Fold as Fold, Unfold as Unfold
from .instancenorm import InstanceNorm1d as InstanceNorm1d, InstanceNorm2d as InstanceNorm2d, \
InstanceNorm3d as InstanceNorm3d
-from .linear import Bilinear as Bilinear, Linear as Linear
+from .linear import Bilinear as Bilinear, Identity as Identity, Linear as Linear
from .loss import BCELoss as BCELoss, BCEWithLogitsLoss as BCEWithLogitsLoss, CTCLoss as CTCLoss, \
CosineEmbeddingLoss as CosineEmbeddingLoss, CrossEntropyLoss as CrossEntropyLoss, \
HingeEmbeddingLoss as HingeEmbeddingLoss, KLDivLoss as KLDivLoss, L1Loss as L1Loss, MSELoss as MSELoss, \
