[PATCH] add securityfs for all LSMs to use

Here's a small patch against 2.6.13-rc2 that adds securityfs, a virtual
fs that all LSMs can use instead of creating their own.  The fs should
be mounted at /sys/kernel/security, and the fs creates that mount point.
This will make the LSB people happy that we aren't creating a new
/my_lsm_fs directory in the root for every different LSM.

It has changed a bit since the last version, thanks to comments from
Mike Waychison.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Chris Wright <chrisw@osdl.org>