Leaves us with lock_kernel for two methods.  Also remove a bogus printk
with no printk level and return -ENOTTY not -EINVAL for correctness.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

(Jens: added smp_lock.h include to pt.c, otherwise it wont compile because
 of missing {un}lock_kernel() definition)
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>