Commit acfa747b introduced the TTY_HUPPING flag to distinguish
closed TTY from currently closing ones. The test in tty_set_ldisc
still remained pointing at the old flag. This causes pppd to
sometimes lapse into uninterruptible sleep when killed and
restarted.
Signed-off-by: NShachar Shemesh <shachar@liveu.tv>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>