backend/drm: stop using surface size for BO

Stop using wlr_drm_surface.{width,height} to figure out the size of a
gbm_bo. In the future we'll stop using wlr_drm_plane.surf, so these will
be zero. Instead, rely on gbm_bo_get_{width,height}.

backend/drm/atomic.c

@@ -139,13 +139,16 @@ static void set_plane_props(struct atomic *atom, struct wlr_drm_backend *drm,
 		goto error;
 	}
 
+	uint32_t width = gbm_bo_get_width(fb->bo);
+	uint32_t height = gbm_bo_get_height(fb->bo);
+
 	// The src_* properties are in 16.16 fixed point
 	atomic_add(atom, id, props->src_x, 0);
 	atomic_add(atom, id, props->src_y, 0);
-	atomic_add(atom, id, props->src_w, (uint64_t)plane->surf.width << 16);
-	atomic_add(atom, id, props->src_h, (uint64_t)plane->surf.height << 16);
-	atomic_add(atom, id, props->crtc_w, plane->surf.width);
-	atomic_add(atom, id, props->crtc_h, plane->surf.height);
+	atomic_add(atom, id, props->src_w, (uint64_t)width << 16);
+	atomic_add(atom, id, props->src_h, (uint64_t)height << 16);
+	atomic_add(atom, id, props->crtc_w, width);
+	atomic_add(atom, id, props->crtc_h, height);
 	atomic_add(atom, id, props->fb_id, fb->id);
 	atomic_add(atom, id, props->crtc_id, crtc_id);
 	atomic_add(atom, id, props->crtc_x, (uint64_t)x);

backend/drm/legacy.c

@@ -81,9 +81,11 @@ static bool legacy_crtc_commit(struct wlr_drm_backend *drm,
 			return false;
 		}
 
-		if (drmModeSetCursor(drm->fd, crtc->id,
-				gbm_bo_get_handle(cursor_fb->bo).u32,
-				cursor->surf.width, cursor->surf.height)) {
+		uint32_t cursor_handle = gbm_bo_get_handle(cursor_fb->bo).u32;
+		uint32_t cursor_width = gbm_bo_get_width(cursor_fb->bo);
+		uint32_t cursor_height = gbm_bo_get_height(cursor_fb->bo);
+		if (drmModeSetCursor(drm->fd, crtc->id, cursor_handle,
+				cursor_width, cursor_height)) {
 			wlr_drm_conn_log_errno(conn, WLR_DEBUG, "drmModeSetCursor failed");
 			return false;
 		}