rwcancel: fix wrong poll event flag on ReadyWrite

It should be POLLIN because closeFd is read-only file.

Signed-off-by: Kurnia D Win <[email protected]>
Signed-off-by: Jason A. Donenfeld <[email protected]>

Author: win-t

rwcancel/rwcancel.go

@@ -64,7 +64,7 @@ func (rw *RWCancel) ReadyRead() bool {
 
 func (rw *RWCancel) ReadyWrite() bool {
 	closeFd := int32(rw.closingReader.Fd())
-	pollFds := []unix.PollFd{{Fd: int32(rw.fd), Events: unix.POLLOUT}, {Fd: closeFd, Events: unix.POLLOUT}}
+	pollFds := []unix.PollFd{{Fd: int32(rw.fd), Events: unix.POLLOUT}, {Fd: closeFd, Events: unix.POLLIN}}
 	var err error
 	for {
 		_, err = unix.Poll(pollFds, -1)