hw/i386/pc: Clean up pc_machine_initfn

To use the newly introduced PC machine class local variable.

Suggested-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <20230609164107.23404-1-suravee.suthikulpanit@amd.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/i386/pc.c

@@ -1867,7 +1867,7 @@ static void pc_machine_initfn(Object *obj)
     pcms->smbios_entry_point_type = pcmc->default_smbios_ep_type;
 
     /* acpi build is enabled by default if machine supports it */
-    pcms->acpi_build_enabled = PC_MACHINE_GET_CLASS(pcms)->has_acpi_build;
+    pcms->acpi_build_enabled = pcmc->has_acpi_build;
     pcms->smbus_enabled = true;
     pcms->sata_enabled = true;
     pcms->i8042_enabled = true;