MINOR: poller: move the call of tv_update_date() back to the pollers

The reason behind this will be to be able to compute a timeout when
busy polling.
diff --git a/src/ev_kqueue.c b/src/ev_kqueue.c
index dc1310c..a894f66 100644
--- a/src/ev_kqueue.c
+++ b/src/ev_kqueue.c
@@ -143,6 +143,7 @@
 			kev,       // struct kevent *eventlist
 			fd,        // int nevents
 			&timeout); // const struct timespec *timeout
+	tv_update_date(delta_ms, status);
 	tv_leaving_poll(delta_ms, status);
 
 	thread_harmless_end();