[PyTorch] Format generated structured kernels code better (#55258)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55258
Prior to this diff, the generated code contained whitespace-only lines and odd indenting. Now, it is easier to read.
ghstack-source-id: 127092678
Test Plan:
Inspect generated RegisterCPU.cpp.
Before: P372666985
After: P372665023
Reviewed By: ezyang
Differential Revision: D27544604
fbshipit-source-id: 03095aa0275e7e817951cf8b303e4ad5cbb486ca
