socketpool: check poll exipred after lisklist inserted
socketpool: check poll exipred after lisklist inserted

Issues #2816

yannick/h2o,h2o/h2o,devnexen/h2o,h2o/h2o,devnexen/h2o,cwyang/h2o,yannick/h2o,devnexen/h2o,yannick/h2o,cwyang/h2o,h2o/h2o,h2o/h2o,h2o/h2o,yannick/h2o,cwyang/h2o,devnexen/h2o,yannick/h2o,cwyang/h2o,devnexen/h2o,devnexen/h2o,yannick/h2o,cwyang/h2o,devnexen/h2o,h2o/h2o,h2o/h2o,yannick/h2o,yannick/h2o,cwyang/h2o,cwyang/h2o,cwyang/h2o,devnexen/h2o,yannick/h2o,h2o/h2o,devnexen/h2o,h2o/h2o