Fix segfault in DRM cursor

backend/drm/drm.c

@@ -503,13 +503,6 @@ static bool wlr_drm_connector_set_cursor(struct wlr_output *output,
 	struct wlr_drm_crtc *crtc = conn->crtc;
 	struct wlr_drm_plane *plane = crtc->cursor;
 
-	if (!buf && update_pixels) {
-		// Hide the cursor
-		plane->cursor_enabled = false;
-		return drm->iface->crtc_set_cursor(drm, crtc, NULL);
-	}
-	plane->cursor_enabled = true;
-
 	// We don't have a real cursor plane, so we make a fake one
 	if (!plane) {
 		plane = calloc(1, sizeof(*plane));
@@ -520,6 +513,13 @@ static bool wlr_drm_connector_set_cursor(struct wlr_output *output,
 		crtc->cursor = plane;
 	}
 
+	if (!buf && update_pixels) {
+		// Hide the cursor
+		plane->cursor_enabled = false;
+		return drm->iface->crtc_set_cursor(drm, crtc, NULL);
+	}
+	plane->cursor_enabled = true;
+
 	if (!plane->surf.gbm) {
 		int ret;
 		uint64_t w, h;