836* tools/mkport.pl: Better detection for
          HAVE_ELF_GETSHDRSTRNDX. Without this, Brendan Giggs
	  "struct sock" test broke.
	  http://sourceforge.net/apps/trac/elftoolchain/wiki/LibElfIncompatibilityRedHatElfUtils
	  has the gory details - they changed (fixed) the return code
	  for elf_getshstrndx which is annoying since we need to know the version
	  of elfutils to see which API it conforms to. I am seriously unimpressed
	  that sprawled through the releases - it was a broken API change and
	  it is a broken API change. WTF are two dyslexically impossible to
	  read function names used?