do not even try to send delayed ack if jiffies did not change since last time
do not even try to send delayed ack if jiffies did not change since last time

git-svn-id: 29c1264a5cf5e3532df57b06678e7347571c1a3c@675 f1ba3bf5-cb5c-402b-92a9-7c6bdc83a356

ananos/xen2mx,ananos/xen2mx,ananos/xen2mx,ananos/open-mx,ananos/xen2mx,ananos/open-mx,ananos/open-mx