use code in module_exit?

[Christoph Hellwig]

All pcmcia drivers have code in module_exit() to walk dev_list
and call detach on all remaining dev_link_t.  But looking at ds.c
we see that we get a module reference before each ->attach and release
the reference only after ->detach so this code is completly superflous.

That's what my testing with orinoco_cs suggest aswell.

Can we just rip out lots of long-obsolete code or did I miss something
obvious?