tests: Relax the limit for rate-limiter tests

Signed-off-by: Bo Chen <[email protected]>

tests/integration.rs

@@ -10644,7 +10644,7 @@ mod rate_limiter {
             } else {
                 parse_fio_output_iops(&output, &fio_ops, num_queues).unwrap()
             };
-            assert!(check_rate_limit(measured_rate, limit_rate, 0.1));
+            assert!(check_rate_limit(measured_rate, limit_rate, 0.2));
         });
 
         let _ = child.kill();