Convert the boot-time host ptrace testing from clone to fork.  They were
essentially doing fork anyway.  This cleans up the code a bit, and makes
valgrind a bit happier about grinding it.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>