[issue6868] Check errno of epoll_ctrl

New submission from shaowei.cui : in selectmodule.c, I found the code of epoll module 'result = epoll_ctl(epfd, op, fd, &ev); if (errno == EBADF) { /* fd already closed */ result = 0; errno = 0; } ' 'man epoll_ctl&#x

[issue6867] return value of epoll.register

New submission from shaowei.cui : help(select.epoll) show 'register(fd[, eventmask]) -> bool', but it return 'None' actually. I view the source code of selectmodule.c that return None actually. The function "pyepoll_internal_ctl(int epfd, int op, PyObje