remove deprecation warning on get_contiguous_memory_format (#37963)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/37963
This function is still widely used in the codebase, so we don't want
to add noise to builds with a bunch of warnings. Seems like the
comment + macro are already pretty good indications that this
functionality is considered legacy
Test Plan: Imported from OSS
Differential Revision: D21434447
Pulled By: suo
fbshipit-source-id: 08162ed6502894ea5d3ccb92dfa0183232cc2ab5
