[JIT] Cleanup some places where we log graphs in executors. (#44588)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/44588
1) SOURCE_DUMP crashes when invoked on a backward graph since
`prim::GradOf` nodes can't be printed as sources (they don't have
schema).
2) Dumping graph each time we execute an optimized plan produces lots of
output in tests where we run the graph multiple times (e.g.
benchmarks). Outputting that on the least level of verbosity seems
like an overkill.
3) Duplicated log statement is removed.
Differential Revision: D23666812
Test Plan: Imported from OSS
Reviewed By: bertmaher
Pulled By: ZolotukhinM
fbshipit-source-id: b9a30e34fd39c85f3e13c3f1e3594e157e1c130f
Author
Mikhail Zolotukhin
