Fix vulkan build on linux and android

tools/vulkan/android/VulkanTestContext_android.cpp

 
 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "VulkanTestContext_android.h"
 
@@ skipping 14 matching lines @@
                                            reinterpret_cast<ContextPlatformData_android*>(platformData);
     VkSurfaceKHR surface;
 
     VkAndroidSurfaceCreateInfoKHR surfaceCreateInfo;
     memset(&surfaceCreateInfo, 0, sizeof(VkAndroidSurfaceCreateInfoKHR));
     surfaceCreateInfo.sType = VK_STRUCTURE_TYPE_ANDROID_SURFACE_CREATE_INFO_KHR;
     surfaceCreateInfo.pNext = nullptr;
     surfaceCreateInfo.flags = 0;
     surfaceCreateInfo.window = androidPlatformData->fNativeWindow;
 
-    VkResult res = createAndroidSurfaceKHR(fBackendContext->fInstance, &surfaceCreateInfo,
+    VkResult res = createAndroidSurfaceKHR(instance, &surfaceCreateInfo,
                                            nullptr, &surface);
     return (VK_SUCCESS == res) ? surface : VK_NULL_HANDLE;
 }
 
 bool VulkanTestContext::canPresent(VkInstance instance, VkPhysicalDevice physDev,
                                    uint32_t queueFamilyIndex) {
     return true;
 }