coll/base: call coll_module_disable only once per module

[gkatev]

Adjust the call to coll_module_disable, so that it only happens once per module (that supports it), instead of once per each coll function that the module provides. The current code does not cause an issue as all components that implement an xx_module_disable correctly zero-out their data after freeing it, but I'd argue that calling it once is more appropriate/safe. I also took the liberty of replacing the list operations with less verbose ones using the opal_list macros.

Signed-off-by: George Katevenis gkatev@ics.forth.gr

[ompiteam-bot]

Can one of the admins verify this patch?

[bosilca]

In today's collective initialization, a module does not know how many references it has (aka how many of its functions are still in the communicator function pointer table), which means there is no safe way to release a module as long as we don't move the refcount accounting in a safe and consistent place.