Apply project formatting rules to ort_aten.cpp (#12294)
* Apply project formatting rules to ort_aten.cpp
Formatting applied by formatting the file in VS Code.
This file is under active development and the inconsistent formatting
was causing friction due to:
1. cpplint job on Pipeline was flagging a lot of style issues,
resulting in a lot of noisy annotations.
2. local edits would result in changes that are not part of the core change.
While there are other files in this part of the source tree with
inconsistent formatting, this file was causing the most friction. We can
come back and address the other files later, which would be a much
larger change.
* Apply consistent pattern for invoker.Invoke(...)
