[api] fix reset for radio only mode (#2859)

src/core/api/instance_api.cpp

@@ -76,12 +76,8 @@ bool otInstanceIsInitialized(otInstance *aInstance)
 
 void otInstanceFinalize(otInstance *aInstance)
 {
-#if OPENTHREAD_MTD || OPENTHREAD_FTD
     Instance &instance = *static_cast<Instance *>(aInstance);
     instance.Finalize();
-#else
-    OT_UNUSED_VARIABLE(aInstance);
-#endif // OPENTHREAD_MTD || OPENTHREAD_FTD
 }
 
 void otInstanceReset(otInstance *aInstance)

src/core/common/instance.cpp

@@ -168,21 +168,23 @@ void Instance::AfterInit(void)
 #endif // OPENTHREAD_MTD || OPENTHREAD_FTD
 }
 
-#if OPENTHREAD_MTD || OPENTHREAD_FTD
 void Instance::Finalize(void)
 {
     VerifyOrExit(mIsInitialized == true);
 
     mIsInitialized = false;
 
+#if OPENTHREAD_MTD || OPENTHREAD_FTD
     IgnoreReturnValue(otThreadSetEnabled(this, false));
     IgnoreReturnValue(otIp6SetEnabled(this, false));
     IgnoreReturnValue(otLinkSetEnabled(this, false));
+#endif
 
 exit:
     return;
 }
 
+#if OPENTHREAD_MTD || OPENTHREAD_FTD
 void Instance::FactoryReset(void)
 {
     GetSettings().Wipe();

src/core/common/instance.hpp

@@ -211,7 +211,6 @@ public:
     }
 #endif
 
-#if OPENTHREAD_MTD || OPENTHREAD_FTD
     /**
      * This method finalizes the OpenThread instance.
      *
@@ -220,6 +219,7 @@ public:
      */
     void Finalize(void);
 
+#if OPENTHREAD_MTD || OPENTHREAD_FTD
     /**
      * This method deletes all the settings stored in non-volatile memory, and then triggers a platform reset.
      *