[nnc] Get rid of fuser trigger counters (#57334)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/57334
Here's a possibly controversial PR. These counters got in the way of
generalizing the fuser tests to handle arbitrary devices, and I guess I'm just
generally skeptical that they provide much value. While true that they let us
observe whether fusion groups were created, we already have assertions based on
the shape of the graph, and I'm not sure that I trust those any less than these
counters.
Test Plan: Imported from OSS
Reviewed By: ZolotukhinM
Differential Revision: D29471484
Pulled By: bertmaher
fbshipit-source-id: f6d76f6e72dbfb581acff1d834b0c74500941b57
