HAL_ChibiOS: fixed gcc9 warnings

libraries/AP_HAL_ChibiOS/system.cpp

@@ -83,7 +83,7 @@ static void save_fault_watchdog(uint16_t line, FaultType fault_type, uint32_t fa
             pd.fault_thd_prio = tp->prio;
             // get first 4 bytes of the name, but only of first fault
             if (tp->name && pd.thread_name4[0] == 0) {
-                strncpy(pd.thread_name4, tp->name, 4);
+                strncpy_noterm(pd.thread_name4, tp->name, 4);
             }
         }
         pd.fault_icsr = SCB->ICSR;