staging: comedi_pci: make comedi_pci_disable() safe to call

staging: comedi_pci: make comedi_pci_disable() safe to call

Currently all the comedi PCI drivers need to do some checking in
their (*detach) before calling comedi_pci_disable() in order to
make sure the PCI device has actually be enabled.

Change the parameter passed to comedi_pci_disable() from a struct
pci_dev pointer to a comedi_device pointer and have comedi_pci_disable()
handle all the checking.

For most comedi PCI drivers this also allows removing the local
variable holding the pointer to the pci_dev. For some of the drivers
comedi_pci_disable can now be used directly as the (*detach) function.

The National Instruments drivers that use the mite module currently
enable/disable the PCI device in the mite module. For those drivers
move the call to comedi_pci_disable into the driver and make sure
dev->iobase is set to a non-zero value.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>