extable: Skip sorting if sorted at build time.

If the build program sortextable has already sorted the exception
table, don't sort it again.

Signed-off-by: David Daney <david.daney@cavium.com>
Link: http://lkml.kernel.org/r/1334872799-14589-3-git-send-email-ddaney.cavm@gmail.com


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>