staging: unisys: visorchipset: Do not use confuse size of long with size of u32

struct visorcipset_device_info defines bus_no and dev_no as u32, while
the deprecated ulong type is 64 bits. Hence avoid promoting the values
to 64 bit just to truncate them again later.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Tested-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>