selinux: Shuffle the sk_security_struct alloc and free routines
The sk_alloc_security() and sk_free_security() functions were only being
called by the selinux_sk_alloc_security() and selinux_sk_free_security()
functions so we just move the guts of the alloc/free routines to the
callers and eliminate a layer of indirection.
Signed-off-by: Paul Moore <paul.moore@hp.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>