migration/colo: Replace QemuSemaphore with QemuEvent

colo_exit_sem and colo_incoming_sem represent one-shot events so they
can be converted into QemuEvent, which is more lightweight.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20250529-event-v5-8-53b285203794@daynix.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 files changed