renderer: do not open-code vrend_renderer_force_ctx_0

We already have a helper for this, let's use it.

Signed-off-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>

src/vrend_renderer.c

@@ -6829,7 +6829,7 @@ int vrend_renderer_transfer_iov(const struct vrend_transfer_info *info,
       return EINVAL;
 
    if (info->context0) {
-      vrend_hw_switch_context(vrend_lookup_renderer_ctx(0), true);
+      vrend_renderer_force_ctx_0();
       ctx = NULL;
    }