new helper: memcpy_to_msg()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

net/ipv4/tcp.c

@@ -1349,7 +1349,7 @@ static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
 
 		if (len > 0) {
 			if (!(flags & MSG_TRUNC))
-				err = memcpy_toiovec(msg->msg_iov, &c, 1);
+				err = memcpy_to_msg(msg, &c, 1);
 			len = 1;
 		} else
 			msg->msg_flags |= MSG_TRUNC;