Avoid double-query with VK_EXT_host_image_copy

[ShabbyX]

The following code does two queries to get the device properties:

VulkanCapsViewer/VulkanDeviceInfoExtensions.cpp

Line 363 in bb8d5e2

if (extensionSupported("VK_EXT_host_image_copy")) {

You can avoid this by providing a large-enough array size to pCopySrcLayouts and pCopyDstLayouts in the very first query. Given the current number of enums in VkImageLayout, an array of say 100 entries should be more than enough for the foreseeable future.