drm/vkms: Remove event from vkms_output

While working on rvkms, I noticed that there's no code that actually uses
the drm_pending_vblank_event that's embedded in vkms_output. So, just drop
the member from the struct.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Tested-by: Louis Chauvet <louis.chauvet@bootlin.com>
Reviewed-by: Maíra Canal <mcanal@igalia.com>
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240703160458.1303872-1-lyude@redhat.com

drivers/gpu/drm/vkms/vkms_drv.h

@@ -103,7 +103,6 @@ struct vkms_output {
 	struct drm_writeback_connector wb_connector;
 	struct hrtimer vblank_hrtimer;
 	ktime_t period_ns;
-	struct drm_pending_vblank_event *event;
 	/* ordered wq for composer_work */
 	struct workqueue_struct *composer_workq;
 	/* protects concurrent access to composer */