Test for AIX sendreply error.

Port to 2.0 of:

commit 11a1419a2afdcef49c44c6d71756fc819b4d0934
Author: lancerus <lancerus@bear108.almaden.ibm.com>
Date:   Thu Feb 14 08:55:02 2013 -0800

Log errno where possible.  Destroy the current xprt connection
if svc_sendreply fails.

Signed-off-by: Matt Benjamin <matt@linuxbox.com>