h2olog: set up one of the tracer functions
h2olog: set up one of the tracer functions

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