staging: comedi: jr3_pci: rename card variable

The local variable `card` in `jr3_pci_auto_attach()` is used to point to
the PCI device `struct pci_dev`.  Rename it to `pcidev`.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>