pc: remove useless hot_add_cpu initialisation

Since 4458fb3a (pc: Eliminate pc_default_machine_options()),
hot_add_cpu is set in pc_machine_class_init(), so we don't
need to set it in pc_q35_machine_options(), pc_i440fx_machine_options()
and xenfv_machine_options(), except to clear it in
pc_i440fx_1_4_machine_opt().
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NEduardo Habkost <ehabkost@redhat.com>
Acked-by: NAnthony PERARD <anthony.perard@citrix.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

hw/i386/pc_piix.c

@@ -426,7 +426,6 @@ static void pc_i440fx_machine_options(MachineClass *m)
 {
     m->family = "pc_piix";
     m->desc = "Standard PC (i440FX + PIIX, 1996)";
-    m->hot_add_cpu = pc_hot_add_cpu;
     m->default_machine_opts = "firmware=bios-256k.bin";
     m->default_display = "std";
 }
@@ -1125,7 +1124,6 @@ static void xenfv_machine_options(MachineClass *m)
     m->desc = "Xen Fully-virtualized PC";
     m->max_cpus = HVM_MAX_VCPUS;
     m->default_machine_opts = "accel=xen";
-    m->hot_add_cpu = pc_hot_add_cpu;
 }
 
 DEFINE_PC_MACHINE(xenfv, "xenfv", pc_xen_hvm_init,

hw/i386/pc_q35.c

@@ -295,7 +295,6 @@ static void pc_q35_machine_options(MachineClass *m)
 {
     m->family = "pc_q35";
     m->desc = "Standard PC (Q35 + ICH9, 2009)";
-    m->hot_add_cpu = pc_hot_add_cpu;
     m->units_per_default_bus = 1;
     m->default_machine_opts = "firmware=bios-256k.bin";
     m->default_display = "std";