As we don't have a late_initcall in ds.c any more, we can't easily
distinguish between in-kernel drivers and those built as modules. This
information was used by cardmgr to detect whether "rmmod" makes
sense. As unloading of modules seems to be deprecated behaviour anyway
in 2.5., and the current driver unloading process is IMO broken
anyway, I don't shed any tears on this lost functionality.