celery_setup: drop param to setup_self and simplify OUR_MODULENAME

celery_setup: drop param to setup_self and simplify OUR_MODULENAME

setup_self used to look like this:
	setup_self(setup_globals_func=setup_globals)
The function isn't called with any param, so drop it.
Rewrite function as needed.

The module var OUR_MODULENAME just has the module's name in
it. This is available as __name__ anyway, so use this to
initialize the var.