Fixed capitalization of oldSwapchain member variable

Author: SaschaWillems

en/03_Drawing_a_triangle/01_Presentation/01_Swap_chain.adoc

@@ -484,7 +484,7 @@ Unless you really need to be able to read these pixels back and get predictable
 createInfo.oldSwapchain = VK_NULL_HANDLE;
 ----
 
-That leaves one last field, `oldSwapChain`.
+That leaves one last field, `oldSwapchain`.
 With Vulkan it's possible that your swap chain becomes invalid or unoptimized while your application is running, for example because the window was resized.
 In that case the swap chain actually needs to be recreated from scratch and a reference to the old one must be specified in this field.
 This is a complex topic that we'll learn more about in xref:03_Drawing_a_triangle/04_Swap_chain_recreation.adoc[a future chapter].

en/03_Drawing_a_triangle/04_Swap_chain_recreation.adoc

@@ -106,7 +106,7 @@ Note that in `chooseSwapExtent` we already query the new window resolution to ma
 That's all it takes to recreate the swap chain!
 However, the disadvantage of this approach is that we need to stop all rendering before creating the new swap chain.
 It is possible to create a new swap chain while drawing commands on an image from the old swap chain are still in-flight.
-You need to pass the previous swap chain to the `oldSwapChain` field in the `VkSwapchainCreateInfoKHR` struct and destroy the old swap chain as soon as you've finished using it.
+You need to pass the previous swap chain to the `oldSwapchain` field in the `VkSwapchainCreateInfoKHR` struct and destroy the old swap chain as soon as you've finished using it.
 
 == Suboptimal or out-of-date swap chain