got Vulkan compiling on Linux again

src/gpu/vk/GrVkGpu.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrVkGpu.h"
 
 #include "GrContextOptions.h"
@@ skipping 688 matching lines @@
     if (!GrSampleCountToVkSampleCount(1, &vkSamples)) {
         return 0;
     }
 
     const VkImageCreateInfo imageCreateInfo = {
         VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO,         // sType
         NULL,                                        // pNext
         0,                                           // VkImageCreateFlags
         VK_IMAGE_TYPE_2D,                            // VkImageType
         pixelFormat,                                 // VkFormat
-        { w, h, 1 },                                 // VkExtent3D
+        { (uint32_t) w, (uint32_t) h, 1 },           // VkExtent3D
         1,                                           // mipLevels
         1,                                           // arrayLayers
         vkSamples,                                   // samples
         imageTiling,                                 // VkImageTiling
         usageFlags,                                  // VkImageUsageFlags
         VK_SHARING_MODE_EXCLUSIVE,                   // VkSharingMode
         0,                                           // queueFamilyCount
         0,                                           // pQueueFamilyIndices
         initialLayout                                // initialLayout
     };
@@ skipping 702 matching lines @@
     int set_a_break_pt_here = 9;
     aglSwapBuffers(aglGetCurrentContext());
 #elif defined(SK_BUILD_FOR_WIN32)
     SwapBuf();
     int set_a_break_pt_here = 9;
     SwapBuf();
 #endif
 #endif
 }