server: Don't create wait object if infinite timeout is passed to NtSetTimer.

server/timer.c

@@ -177,6 +177,7 @@ static int set_timer( struct timer *timer, timeout_t expire, unsigned int period
     timer->callback = callback;
     timer->arg      = arg;
     if (callback) timer->thread = (struct thread *)grab_object( current );
+    if (expire != TIMEOUT_INFINITE)
         timer->timeout = add_timeout_user( expire, timer_callback, timer );
     return signaled;
 }