hw/xen: Rename 'ram_memory' global variable as 'xen_memory'

To avoid a potential global variable shadow in
hw/i386/pc_piix.c::pc_init1(), rename Xen's
"ram_memory" as "xen_memory".

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20231114143816.71079-11-philmd@linaro.org>
4 files changed