Change SetOutputSize in ConvTransposeUnpoolBaseOp (#16179)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16179
to avoid passing partially initialized Tensor around.
Reviewed By: ezyang
Differential Revision: D13744009
fbshipit-source-id: 4c545765e1cd164b3e87ce08ec4c1cb1e37e2b8f
