staging: comedi: ni_labpc: use module_comedi_pci_driver()

Use the macro `module_comedi_pci_driver(comedi_driver, pci_driver)` to
register the module as a Comedi PCI driver if the module supports PCI
devices, otherwise use `module_comedi_driver(comedi_driver)` to register
it as an ordinary Comedi driver.  Rename variables and functions that
have prefix `driver_` for consistency.  Set the `name` member of the
`struct pci_driver` variable in its initializer instead of initializing
it in the module initialization function.

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