fix typo in docstring

Author: alykhantejani

torch/nn/functional.py

@@ -1008,7 +1008,7 @@ def affine_grid(theta, size):
  Args:
  theta (Variable): input batch of affine matrices (N x 2 x 3)
  size (torch.Size): the target output image size (N x C x H x W)
- Example: torch.Size(32, 3, 24, 24)
+ Example: torch.Size((32, 3, 24, 24))
 
  Returns:
  output (Variable): output Tensor of size (N x H x W x 2)