blocking_worker: Make use of templated lambda

We can simplify this a little by explicitly specifying the typename for
the lambda function.

src/core/hle/service/sockets/blocking_worker.h

@@ -109,9 +109,8 @@ private:
         while (keep_running) {
             work_event.Wait();
 
-            const auto visit_fn = [service, &keep_running](auto&& w) {
+            const auto visit_fn = [service, &keep_running]<typename T>(T&& w) {
-                using T = std::decay_t<decltype(w)>;
+                if constexpr (std::is_same_v<std::decay_t<T>, std::monostate>) {
-                if constexpr (std::is_same_v<T, std::monostate>) {
                     keep_running = false;
                 } else {
                     w.Execute(service);