Char: stallion, remove bottomhalf

- tty_hangup schedules a bottomhalf itself, tty_wakeup doesn't need it
- call the CD code (part of work handler previously) directly from the code
  (it wakes somebody up or calls tty_hangup at worse)

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>