staging: vt6655: Remove unused member from struct vnt_private

The pci_state member of struct vnt_private is used nowhere in the code,
so remove it. Supposedly it was used to save the PCI configuration space
which is now done using pci_save_state().

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>