Fix test_namedtuple_return (#20212)
Summary:
Fixes: https://github.com/pytorch/pytorch/issues/20198
Input matrix created randomly might be rank deficient or not positive semidefinite
Not tested yet, will look at CI.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/20212
Differential Revision: D15241331
Pulled By: zou3519
fbshipit-source-id: b71cdc5d5b622b5423a43b86d75cfaf3d9484100
