vulkaninfo: use patch version from instance

vulkaninfo: use patch version from instance

When the original vkEnumerateInstanceVersion was implemented, the loader always return
0 for the patch. This has since been corrected, but in the mean time vulkaninfo used the
hardcoded VK_HEADER_VERSION to get the patch information. Now vulkaninfo will use the
patch version from the instance, unless it is zero, in which it will then fallback
to VK_HEADER_VERSION's patch.

Changes to be committed:
	modified:   vulkaninfo/vulkaninfo.h

Change-Id: If0a63534253afadccbad50c6256cdef8016222c1