staging: unisys: fix indentation on vbuschannel_devinfo_to_string()

Fix the parameter indentation for vbuschannel_devinfo_to_string(), in
vbusdeviceinfo.h.

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