sctp: remove redundant null check on asoc

In sctp_err_lookup, goto out while the asoc is not NULL, so remove the
check NULL. Also, in sctp_err_finish which called by sctp_v4_err and
sctp_v6_err, they pass asoc to sctp_err_finish while the asoc is not
NULL, so remove the check.

Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sctp/input.c

@@ -536,17 +536,15 @@ struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *skb,
 	return sk;
 
 out:
-	if (asoc)
-		sctp_association_put(asoc);
+	sctp_association_put(asoc);
 	return NULL;
 }
 
 /* Common cleanup code for icmp/icmpv6 error handler. */
 void sctp_err_finish(struct sock *sk, struct sctp_association *asoc)
 {
 	sctp_bh_unlock_sock(sk);
-	if (asoc)
-		sctp_association_put(asoc);
+	sctp_association_put(asoc);
 }
 
 /*