[quant][graphmode][fix] Make it work with CallMethod on non-Module objects (#41576)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/41576
Previously we are assuming CallMethod only happens on module instances,
but it turns out this is not true, this PR fixes this issue.
Test Plan: Imported from OSS
Reviewed By: z-a-f
Differential Revision: D22592789
fbshipit-source-id: 48217626d9ea8e82536f00a296b8f9a471582ebe
