Fix variable checking in THCPModule_setRNGState (#17474)
Summary:
See https://github.com/pytorch/pytorch/pull/16325/files#r259576901
Pull Request resolved: https://github.com/pytorch/pytorch/pull/17474
Differential Revision: D14209549
Pulled By: yf225
fbshipit-source-id: 2ae091955ae17f5d1540f7d465739c4809c327f8
