fix Warning

qt6-after/qt6-migrated-legatus/Lts/Services/ServiceManagement/main.cpp

@@ -54,9 +54,12 @@ static void daemonize()
     exit(EXIT_FAILURE);
 
   /* Redirect standard files to /dev/null */
-  freopen("/dev/null", "r", stdin);
-  freopen("/dev/null", "w", stdout);
-  freopen("/dev/null", "w", stderr);
+  #pragma GCC diagnostic push
+  #pragma GCC diagnostic ignored "-Wunused-result"
+  (void)freopen("/dev/null", "r", stdin);
+  (void)freopen("/dev/null", "w", stdout);
+  (void)freopen("/dev/null", "w", stderr);
+  #pragma GCC diagnostic pop
 #endif
 }