selinux: always call sk_security_struct sksec

trying to grep everything that messes with a sk_security_struct isn't easy
since we don't always call it sksec.  Just rename everything sksec.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

diff --cc security/selinux/hooks.c
Simple merge

diff --cc security/selinux/include/netlabel.h
Simple merge

diff --cc security/selinux/netlabel.c
Simple merge