wined3d: Use context_acquire() in wined3d_swapchain_cs_init().

dlls/wined3d/context.c

@@ -4264,7 +4264,8 @@ struct wined3d_context *context_acquire(const struct wined3d_device *device,
     {
         TRACE("Rendering onscreen.\n");
 
-        context = swapchain_get_context(texture->swapchain);
+        if (!(context = swapchain_get_context(texture->swapchain)))
+            return NULL;
     }
     else
     {
@@ -4274,8 +4275,8 @@ struct wined3d_context *context_acquire(const struct wined3d_device *device,
          * context for the primary swapchain. */
         if (current_context && current_context->device == device)
             context = current_context;
-        else
-            context = swapchain_get_context(device->swapchains[0]);
+        else if (!(context = swapchain_get_context(device->swapchains[0])))
+            return NULL;
     }
 
     context_activate(context, texture, sub_resource_idx);

dlls/wined3d/swapchain.c

@@ -720,20 +720,20 @@ static void wined3d_swapchain_apply_sample_count_override(const struct wined3d_s
 static void wined3d_swapchain_cs_init(void *object)
 {
     struct wined3d_swapchain *swapchain = object;
+    struct wined3d_context *context;
 
-    if (!(swapchain->context[0] = context_create(swapchain)))
+    if (!(context = context_acquire(swapchain->device, swapchain->front_buffer, 0)))
     {
-        WARN("Failed to create context.\n");
+        WARN("Failed to acquire context.\n");
         return;
     }
-    swapchain->num_contexts = 1;
 
     if (wined3d_settings.offscreen_rendering_mode != ORM_FBO
             && (!swapchain->desc.enable_auto_depth_stencil
             || swapchain->desc.auto_depth_stencil_format != swapchain->ds_format->id))
         FIXME("Add OpenGL context recreation support.\n");
 
-    context_release(swapchain->context[0]);
+    context_release(context);
 }
 
 void swapchain_set_max_frame_latency(struct wined3d_swapchain *swapchain, const struct wined3d_device *device)