hle: service: ldn: IUserLocalCommunicationService: Indicate that LDN is disabled.

- Fixes crash on Pokemon Sword/Shield when pressing 'Y'.

src/core/CMakeLists.txt

@@ -400,6 +400,7 @@ add_library(core STATIC
     hle/service/hid/controllers/xpad.h
     hle/service/lbl/lbl.cpp
     hle/service/lbl/lbl.h
+    hle/service/ldn/errors.h
     hle/service/ldn/ldn.cpp
     hle/service/ldn/ldn.h
     hle/service/ldr/ldr.cpp

src/core/hle/service/ldn/errors.h

@@ -0,0 +1,13 @@
+// Copyright 2021 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/hle/result.h"
+
+namespace Service::LDN {
+
+constexpr ResultCode ERROR_DISABLED{ErrorModule::LDN, 22};
+
+} // namespace Service::LDN

src/core/hle/service/ldn/ldn.cpp

@@ -6,6 +6,7 @@
 
 #include "core/hle/ipc_helpers.h"
 #include "core/hle/result.h"
+#include "core/hle/service/ldn/errors.h"
 #include "core/hle/service/ldn/ldn.h"
 #include "core/hle/service/sm/sm.h"
 
@@ -140,10 +141,11 @@ public:
 
     void Initialize2(Kernel::HLERequestContext& ctx) {
         LOG_WARNING(Service_LDN, "(STUBBED) called");
-        // Result success seem make this services start network and continue.
-        // If we just pass result error then it will stop and maybe try again and again.
+
+        // Return the disabled error to indicate that LDN is currently unavailable, otherwise games
+        // will continue to try to make a connection.
         IPC::ResponseBuilder rb{ctx, 2};
-        rb.Push(RESULT_UNKNOWN);
+        rb.Push(ERROR_DISABLED);
     }
 };