strat: build sysmodules with -Wextra/-Werror

stratosphere/ams_mitm/source/fs_mitm/fsmitm_module.cpp

@@ -64,7 +64,7 @@ namespace ams::mitm::fs {
 
         os::ThreadType g_extra_threads[NumExtraThreads];
 
-        void LoopServerThread(void *arg) {
+        void LoopServerThread(void *) {
             /* Loop forever, servicing our services. */
             g_server_manager.LoopProcess();
         }
@@ -98,7 +98,7 @@ namespace ams::mitm::fs {
 
     }
 
-    void MitmModule::ThreadFunction(void *arg) {
+    void MitmModule::ThreadFunction(void *) {
         /* Create fs mitm. */
         R_ABORT_UNLESS((g_server_manager.RegisterMitmServer<FsMitmService>(PortIndex_Mitm, MitmServiceName)));