staging: unisys: refactor ULTRA_VBUS_HEADERINFO

Remove the typedef and rename to struct spar_vbus_headerinfo. Fix CamelCase
member names:

structBytes => struct_bytes
deviceInfoStructBytes => device_info_struct_bytes
devInfoCount => dev_info_count
chpInfoByteOffset => chp_info_offset
busInfoByteOffset => bus_info_offset
devInfoByteOffset => dev_info_offset

Update all references to changed names.

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