Revert "pktcdvd: push BKL down into driver"

This reverts commit 5b6155ee, because
the block device ioctl's really aren't ready for it.

In particular, the "struct file *" and the "struct inode *" arguments do
not necessarily match, which means that the unlocked version of the
ioctl (that only gets a "struct file *") isn't actually able to handle
the cases it needs to handle.

This fixes bugzilla

	http://bugzilla.kernel.org/show_bug.cgi?id=11401



Reported-and-bisected-by: Laurent Riffard <laurent.riffard@free.fr>
Acked-by: Peter Osterlund <petero2@telia.com>
Cc: Alan Cox <alan@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>