Revert "[fx] change from #users to num_users in graph printout (#101140)"
This reverts commit e568c5a18d0fb390437912e13c96e29697af27ec.
Reverted https://github.com/pytorch/pytorch/pull/101140 on behalf of https://github.com/jeanschmidt due to There are internal changes to this commit that are preventing landing, so I am reverting to unblock the diff train ([comment](https://github.com/pytorch/pytorch/pull/101140#issuecomment-1547989487))
