This reverts commit a6540f73, as
requested by Alan:

  "... as it was wrong, the pty code is now fixed and the fact this
   isn't reverted is breaking pptp setups."
Requested-by: NAlan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>