set default n_scan value to 10 for insn demo, added check that it is not set larger than MAX_SAMPLES
set default n_scan value to 10 for insn demo, added check that it is
not set larger than MAX_SAMPLES

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