demo/tut3.c: memset options to 0 before modifying
demo/tut3.c: memset options to 0 before modifying

options.verbose was used uninitialized.

olsonse/comedilib,Linux-Comedi/comedilib,olsonse/comedilib,olsonse/comedilib,Linux-Comedi/comedilib,olsonse/comedilib,olsonse/comedilib,olsonse/comedilib,Linux-Comedi/comedilib,Linux-Comedi/comedilib,Linux-Comedi/comedilib,Linux-Comedi/comedilib