The Xen 4.1 probe never uses the return value from xc_interface_open(),
so was provoking a compiler warning on newer gcc. Fix by not bothering
to put the return value anywhere.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>