Also vectorize complex types in fill. (#34973)
Summary:
Given that complex types have also been vectorized, there is no need to
handle complex types differently in fill.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34973
Differential Revision: D20551014
Pulled By: ezyang
fbshipit-source-id: e0cb519aa17f90b7a2d70700b32b80acb0d41b14
