Chapter 1: Vulkan Init Code using invalid variable name for create_swapchain()

[Fabxx]

the following functions uses:

void VulkanEngine::init_swapchain()
{
	create_swapchain(_windowExtent.width, _windowExtent.height);
}

did you mean to use this?

void VulkanEngine::init_swapchain()
{
	create_swapchain(_swapchainExtent.width, _swapchainExtent.height);
}