machine: Remove QEMUMachine indirection from MachineClass

No need to go through qemu_machine field. Use
MachineClass fields directly.

Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/qmp.c b/qmp.c
index 74107be..c4836df 100644
--- a/qmp.c
+++ b/qmp.c
@@ -117,8 +117,8 @@
     MachineClass *mc;
 
     mc = MACHINE_GET_CLASS(current_machine);
-    if (mc->qemu_machine->hot_add_cpu) {
-        mc->qemu_machine->hot_add_cpu(id, errp);
+    if (mc->hot_add_cpu) {
+        mc->hot_add_cpu(id, errp);
     } else {
         error_setg(errp, "Not supported");
     }