pptp: Remove unused variable in pptp_release()

Variable opt in pptp_release() is set but never used, thus needs to be
removed.
Signed-off-by: Christos Gkekas <chris.gekas@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ppp/pptp.c

@@ -506,7 +506,6 @@ static int pptp_release(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
 	struct pppox_sock *po;
-	struct pptp_opt *opt;
 	int error = 0;
 
 	if (!sk)
@@ -520,7 +519,6 @@ static int pptp_release(struct socket *sock)
 	}
 
 	po = pppox_sk(sk);
-	opt = &po->proto.pptp;
 	del_chan(po);
 
 	pppox_unbind_sock(sk);