message: Fix the validation error for buffer copy
diff: @@ -416,7 +416,7 @@ namespace vks
  VK_CHECK_RESULT(vkAllocateMemory(logicalDevice, &memAlloc, nullptr, &buffer->memory));
  buffer->alignment = memReqs.alignment;
  - buffer->size = memAlloc.allocationSize;
  + buffer->size = size;
  buffer->usageFlags = usageFlags;
  buffer->memoryPropertyFlags = memoryPropertyFlags;
  