sctp: Move sctp_v4_dst_saddr out of loop

There's no need to execute sctp_v4_dst_saddr() for each
iteration, just move it out of loop.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sctp/protocol.c

@@ -470,11 +470,11 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
 		/* Walk through the bind address list and look for a bind
 		 * address that matches the source address of the returned dst.
 		 */
+		sctp_v4_dst_saddr(&dst_saddr, dst, htons(bp->port));
 		rcu_read_lock();
 		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 			if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC))
 				continue;
-			sctp_v4_dst_saddr(&dst_saddr, dst, htons(bp->port));
 			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
 				goto out_unlock;
 		}