winpr: fix #6970

Timer changes were wrong when timerfd support is not available (no valid file
descriptor returned by GetFd calls).

(cherry picked from commit 5e3e2cd9fd)

winpr/libwinpr/synch/timer.c

@@ -344,6 +344,7 @@ HANDLE CreateWaitableTimerA(LPSECURITY_ATTRIBUTES lpTimerAttributes, BOOL bManua
 #if defined(TIMER_IMPL_DISPATCH) || defined(TIMER_IMPL_POSIX)
 		if (!winpr_event_init(&timer->event))
 			goto fail;
+		timer->fd = timer->event.fds[0];
 #endif
 
 #if defined(TIMER_IMPL_DISPATCH)