Close the device gracefully when cherrypy exits When the cherrypy server exits, remember to close the touch device gracefully. This prevents any local/remote zombie processes. BUG=chromium:443539 TEST=Manually execute webplot.py on a chrome os machine, and press ctrl-c to interrupt the server. Confirm that there are no evtest and ssh zombie processes. Change-Id: Ib8bd927cf78a4cb620f021298ca2cb392f9efab5 Reviewed-on: https://chromium-review.googlesource.com/241366 Reviewed-by: Charlie Mooney <[email protected]> Commit-Queue: Shyh-In Hwang <[email protected]> Tested-by: Shyh-In Hwang <[email protected]>