hw/core/null-machine: Do not initialize unused chardev backends
The MachineClass uses an inverted logic (inherited from the
PC machines [*]) to create the chardev backends for the default
devices (see commits
998bbd74b9d..
aa40fc9c964 and
ac33f8fad14).
As the none-machine doesn't have any hardware device, it is
pointless to initialize chardev backends. Fix by setting the
'no_defaults' bits in its MachineClass.
Suggested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <
20200624105611.1049-1-f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>