staging: unisys: remove goto in get_vbus_header_info

Remove the rc, the = -1, and all the goto mess here and just return
directly with a meaningful error number.

The caller only cares about success/failure right now, that needs to be
addressed in a later patch series.

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