machine: default -M mem-merge to off is QEMU_MADV_MERGEABLE is not available

Otherwise, starting any guest on a non-Linux guests results in

qemu-system-arm: Couldn't set property 'merge' on 'memory-backend-ram': Invalid argument

Cc: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 file changed