autogen.sh: Exit script on first error
autogen.sh: Exit script on first error

libusbx.git commit c74fe3ab703a28c6d8c3755213e3736c5d1eb35e

legege/libusb,tenderlove/libusb,ashima/libusb,bert/libusb,tenderlove/libusb,hjelmn/libusb-darwin,legege/libusb,bert/libusb,hjelmn/libusb-darwin,legege/libusb,ashima/libusb,dasdeepak/libusb,dasdeepak/libusb,dasdeepak/libusb,ashima/libusb