lsm: remove current_security()

There are no remaining callers and it really is unsafe in the brave
new world of LSM stacking.

Acked-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

include/linux/cred.h

@@ -384,7 +384,6 @@ static inline void put_cred(const struct cred *_cred)
 #define current_fsgid() 	(current_cred_xxx(fsgid))
 #define current_cap()		(current_cred_xxx(cap_effective))
 #define current_user()		(current_cred_xxx(user))
-#define current_security()	(current_cred_xxx(security))
 
 extern struct user_namespace init_user_ns;
 #ifdef CONFIG_USER_NS