[mle] change Restore() to return void (#7537)

src/core/common/instance.cpp

@@ -189,7 +189,7 @@ void Instance::AfterInit(void)
     // Restore datasets and network information
 
     Get<Settings>().Init();
-    IgnoreError(Get<Mle::MleRouter>().Restore());
+    Get<Mle::MleRouter>().Restore();
 
 #if OPENTHREAD_CONFIG_RADIO_LINK_TREL_ENABLE
     Get<Trel::Link>().AfterInit();

src/core/thread/mle.cpp

@@ -310,9 +310,8 @@ exit:
     return;
 }
 
-Error Mle::Restore(void)
+void Mle::Restore(void)
 {
-    Error                 error = kErrorNone;
     Settings::NetworkInfo networkInfo;
     Settings::ParentInfo  parentInfo;
 
@@ -323,7 +322,7 @@ Error Mle::Restore(void)
     Get<DuaManager>().Restore();
 #endif
 
-    SuccessOrExit(error = Get<Settings>().Read(networkInfo));
+    SuccessOrExit(Get<Settings>().Read(networkInfo));
 
     Get<KeyManager>().SetCurrentKeySequence(networkInfo.GetKeySequence());
     Get<KeyManager>().SetMleFrameCounter(networkInfo.GetMleFrameCounter());
@@ -356,9 +355,7 @@ Error Mle::Restore(void)
 
     if (!IsActiveRouter(networkInfo.GetRloc16()))
     {
-        error = Get<Settings>().Read(parentInfo);
-
-        if (error != kErrorNone)
+        if (Get<Settings>().Read(parentInfo) != kErrorNone)
         {
             // If the restored RLOC16 corresponds to an end-device, it
             // is expected that the `ParentInfo` settings to be valid
@@ -390,11 +387,11 @@ Error Mle::Restore(void)
     }
 #endif
 
-    // Sucessfully restored the network information from non-volatile settings after boot.
+    // Successfully restored the network information from non-volatile settings after boot.
     mHasRestored = true;
 
 exit:
-    return error;
+    return;
 }
 
 Error Mle::Store(void)

src/core/thread/mle.hpp

@@ -144,13 +144,10 @@ public:
     void Stop(void) { Stop(kUpdateNetworkDatasets); }
 
     /**
-     * This method restores network information from non-volatile memory.
-     *
-     * @retval kErrorNone      Successfully restore the network information.
-     * @retval kErrorNotFound  There is no valid network information stored in non-volatile memory.
+     * This method restores network information from non-volatile memory (if any).
      *
      */
-    Error Restore(void);
+    void Restore(void);
 
     /**
      * This method stores network information into non-volatile memory.