security: fix return of void-valued expressions

Fix several warnings generated by sparse of the form
"returning void-valued expression".

Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>

security/security.c

@@ -895,7 +895,7 @@ EXPORT_SYMBOL(security_secctx_to_secid);
 
 void security_release_secctx(char *secdata, u32 seclen)
 {
-	return security_ops->release_secctx(secdata, seclen);
+	security_ops->release_secctx(secdata, seclen);
 }
 EXPORT_SYMBOL(security_release_secctx);
 
@@ -1012,12 +1012,12 @@ int security_sk_alloc(struct sock *sk, int family, gfp_t priority)
 
 void security_sk_free(struct sock *sk)
 {
-	return security_ops->sk_free_security(sk);
+	security_ops->sk_free_security(sk);
 }
 
 void security_sk_clone(const struct sock *sk, struct sock *newsk)
 {
-	return security_ops->sk_clone_security(sk, newsk);
+	security_ops->sk_clone_security(sk, newsk);
 }
 
 void security_sk_classify_flow(struct sock *sk, struct flowi *fl)