[PATCH] libata: add ATA exceptions chapter to doc

 Hello, Jeff.

This patch adds ATA errors & exceptions chapter to
Documentation/DocBook/libata.tmpl.  As suggested, the chapter is
placed before low level driver specific chapters.  Contents are
unchanged from the last posting.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>