pata_pcmcia: Fix oops in 2.6.21-rc1

Manuel Lass reports:
> This bug is also present in 2.6.21-rc1, and this patch
> indeed fixes it.

The change to the devres layer re-orders the execution of cleanup
functions and in turn causes the pcmcia layer to oops as it zaps a
pointer now needed later on. We simply leave the pointer alone.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>