strat: build sysmodules with -Wextra/-Werror

stratosphere/ams_mitm/source/set_mitm/setmitm_module.cpp

@@ -64,7 +64,7 @@ namespace ams::mitm::settings {
 
     }
 
-    void MitmModule::ThreadFunction(void *arg) {
+    void MitmModule::ThreadFunction(void *) {
         /* Wait until initialization is complete. */
         mitm::WaitInitialized();
 

stratosphere/ams_mitm/source/set_mitm/setsys_mitm_service.hpp

@@ -35,6 +35,7 @@ namespace ams::mitm::settings {
                 /* We will mitm:
                  * - everything, because we want to intercept all settings requests.
                  */
+                AMS_UNUSED(client_info);
                 return true;
             }
         public: