Fix unchecked return value of osmo_libusb_init()

Fixes: CID#307501: Unchecked return value (CHECKED_RETURN)
Change-Id: Ic1f600dfd44d15da165a17d84f0faab6f6fd69c3
diff --git a/host/src/simtrace2_usb.c b/host/src/simtrace2_usb.c
index 8ebc4f7..b329ead 100644
--- a/host/src/simtrace2_usb.c
+++ b/host/src/simtrace2_usb.c
@@ -78,7 +78,7 @@
 int main(int argc, char **argv)
 {
 	osmo_init_logging2(NULL, &log_info);
-	osmo_libusb_init(NULL);
+	OSMO_ASSERT(osmo_libusb_init(NULL) == 0);
 	find_devices();
 	return 0;
 }