While looking in the code I discovered that alpha has fallen behind because
it doesn't use sys_getppid.  The problem is that it doesn't follow the task
struct to the task_group_leader.
Acked-by: NRichard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>