demos: Fix fence sync after new throttling scheme
demos: Fix fence sync after new throttling scheme

f06ab9 cube: Throttle rendering rather than presentation didn't
remove the AMD workaround and didn't consider the VK_ERROR_OUT_OF_DATE_KHR
path through resize.

Change-Id: Ib29bffb5b3c2a82456ad734424af3a9348e897c5

KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools