staging: unisys: remove pointless init of rc in chipset_device_create()

The value of rc is set by calling a function, so there's no need to
initialize it to -1, or anything at all.

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