qdev: Convert to qdev_unrealize() with Coccinelle

For readability, and consistency with qbus_realize().

Coccinelle script:

    @ depends on !(file in "hw/core/qdev.c")@
    typedef DeviceState;
    DeviceState *dev;
    symbol false, error_abort;
    @@
    -    object_property_set_bool(OBJECT(dev), false, "realized", &error_abort);
    +    qdev_unrealize(dev);

    @ depends on !(file in "hw/core/qdev.c") && !(file in "hw/core/bus.c")@
    expression dev;
    symbol false, error_abort;
    @@
    -    object_property_set_bool(OBJECT(dev), false, "realized", &error_abort);
    +    qdev_unrealize(DEVICE(dev));

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-8-armbru@redhat.com>