Networking: Move net/inet/net_monitor.c to net/tcp/tcp_monitor.c in preparation for design change to fix monitoring of duplicated sockets.

libc/wqueue/work_queue.c

@@ -152,7 +152,9 @@ int work_queue(int qid, FAR struct work_s *work, worker_t worker,
     {
       /* Cancel any pending work in the work stucture */
 
-      work_cancel(qid, work);
+      (void)work_cancel(qid, work);
+
+      /* Then queue the new work */
 
       return work_qqueue(&g_usrwork, work, worker, arg, delay);
     }