Revert D28052211: [paramcomms] support for in and out split sizes
Test Plan: revert-hammer
Differential Revision:
D28052211 (https://github.com/pytorch/pytorch/commit/866b19e95d1b28fee07161e92692d2cccc788dcd)
Original commit changeset: 4ab7d425fc72
fbshipit-source-id: 80c001ddcb3730f0487adddf66d9166f53c45a8c
