suppress 'interrupted [code -10]' log message. resolve #87 (#121)

libusb.go

@@ -188,7 +188,10 @@ func (libusbImpl) handleEvents(c *libusbContext, done <-chan struct{}) {
 		default:
 		}
 		if errno := C.libusb_handle_events_timeout_completed((*C.libusb_context)(c), &tv, nil); errno < 0 {
-			log.Printf("handle_events: error: %s", Error(errno))
+			// handler can be interrupted by a signal and this doesn't indicate an error, we'll retry on the next loop iteration
+			if Error(errno) != ErrorInterrupted {
+				log.Printf("handle_events: error: %s", Error(errno))
+			}
 		}
 	}
 }