Kernel/IPC: Put a thread to sleep when performing an LLE IPC request.

It will be awoken when the server replies to the request via svcReplyAndReceive.

src/core/hle/kernel/server_session.cpp

@@ -63,6 +63,9 @@ ResultCode ServerSession::HandleSyncRequest(SharedPtr<Thread> thread) {
     if (hle_handler != nullptr) {
         hle_handler->HandleSyncRequest(SharedPtr<ServerSession>(this));
     } else {
+        // Put the thread to sleep until the server replies, it will be awoken in
+        // svcReplyAndReceive.
+        thread->status = THREADSTATUS_WAIT_IPC;
         // Add the thread to the list of threads that have issued a sync request with this
         // server.
         pending_requesting_threads.push_back(std::move(thread));