[PATCH] selinux: remove security struct magic number fields and tests

Remove the SELinux security structure magic number fields and tests, along
with some unnecessary tests for NULL security pointers.  These fields and
tests are leftovers from the early attempts to support SELinux as a
loadable module during LSM development.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>