if ((ret = libusb_release_interface(usb->devhdl, 0)))
sr_err("Failed to release interface 0: %s.\n", libusb_error_name(ret));
if ((ret = libusb_release_interface(usb->devhdl, 0)))
sr_err("Failed to release interface 0: %s.\n", libusb_error_name(ret));