Fixed alternate_setting in tutorial.
Fixed alternate_setting in tutorial.

Typo and missing dev parameter.

swinman/pyusb,makerbot/pyusb,karlp/pyusb,h3nj3/pyusb,makerbot/pyusb,h3nj3/pyusb,kopchik/pyusb,AlanJAS/pyusb,rabryan/pyusb,swinman/pyusb,kopchik/pyusb,karlp/pyusb,AlanJAS/pyusb,rabryan/pyusb