bufio.NewReader.ReadString blocks even
when the process received syscall.SIGKILL.
Remove ptyMu mutex and make ReadString return
when *os.File is closed.
Signed-off-by: Gyuho Lee <gyuhox@gmail.com>
pkg/ is a collection of utility packages used by etcd without being specific to etcd itself. A package belongs here
only if it could possibly be moved out into its own repository in the future.