zephyr/main: nlr_jump_fail: Fix noreturn warning.

zephyr/main.c

@@ -142,7 +142,8 @@ mp_obj_t mp_builtin_open(size_t n_args, const mp_obj_t *args, mp_map_t *kwargs)
 }
 MP_DEFINE_CONST_FUN_OBJ_KW(mp_builtin_open_obj, 1, mp_builtin_open);
 
-void nlr_jump_fail(void *val) {
+NORETURN void nlr_jump_fail(void *val) {
+    while (1);
 }
 
 void NORETURN __fatal_error(const char *msg) {