nvidia-detect: pass __u16 argument to function nv_lookup_device_id()

Function nv_lookup_device_id() expects an int as it's argument but
receives dev->device_id which is __u16. Making the pci_ids[] arrays
unsigned short and passing __u16 to nv_lookup_device_id() saves 1.8K on
the compiled program size (64-bit).

Signed-off-by: Philip J Perry <phil@elrepo.org>