Migrate away from using Variable( in test_nn.py (#26077)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26077
As per #26071, we would like to get rid of the calls to Variable(
where possible. This diff removes the calls in the test file test_nn.py. The
unit tests should all still pass as expected.
ghstack-source-id: 90086624
Test Plan: tests in `test_nn.py` should all pass.
Differential Revision: D17336484
fbshipit-source-id: 43fc7bd0b0be835ae89d06162ce1cbe4e0056d91
