update mkldnn-bridge to avoid mem leak (#22392)
Summary:
fix the memory leak issue exposed by https://github.com/pytorch/pytorch/issues/21537
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22392
Test Plan: {F164886124}
Reviewed By: yinghai
Differential Revision: D16074150
Pulled By: bddppq
fbshipit-source-id: b70192aad3d531f349fea5d2d477b827715a2363
