qla2xxx: Fix schedule_delayed_work() for target timeout calculations

This patch fixes two cases in qla_target.c code where the
schedule_delayed_work() value was being incorrectly calculated
from sess->expires - jiffies.

Signed-off-by: Shivaram U <shivaram.u@quadstor.com>
Cc: <stable@vger.kernel.org> #3.6+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>