xive: Trivial fix for compilation error when enabling xive debug
xive: Trivial fix for compilation error when enabling xive debug

Without this, we get:

hw/xive.c: In function ‘xive_special_cache_check’:
hw/xive.c:2982:9: error: missing initializer for field ‘w0’ of
‘struct xive_vp’ [-Werror=missing-field-initializers]

Signed-off-by: Guilherme G. Piccoli <228b0c6e779d898ee58597ae6ee4e429ef9789d9@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>

shenki/skiboot,open-power/skiboot,qemu/skiboot,legoater/skiboot,shenki/skiboot,shenki/skiboot,stewart-ibm/skiboot,legoater/skiboot,legoater/skiboot,shenki/skiboot,legoater/skiboot,stewart-ibm/skiboot,qemu/skiboot,open-power/skiboot,legoater/skiboot,qemu/skiboot,stewart-ibm/skiboot,qemu/skiboot,open-power/skiboot,shenki/skiboot,qemu/skiboot,open-power/skiboot,open-power/skiboot