TS-2137: Use relative timeout in EventNotify::timedwait()

1) Use relative timeout in EventNotify::timedwait() function.
2) Remove unused m_name variable.
3) Use the correct marco HAVE_EVENTFD instead of TS_HAS_EVENTFD which
   is outdated.

Signed-off-by: Yunkai Zhang <qiushu.zyk@taobao.com>