Replace the two-field design (gfx_update void callback + gfx_update_async
flag) with a single bool return value from gfx_update. Returning true
means the update completed synchronously and graphic_hw_update_done()
should be called by the console layer. Returning false means the update
is deferred and the device will call graphic_hw_update_done() itself
later (as done by QXL/SPICE and Apple GFX).
This simplifies the interface and makes the async contract explicit at
each call site rather than relying on a separate struct field.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
c6e94d24fb