emb6_sock_udp: copy receive remote correctly

The `src` member of `sock_udp_t` for `emb6` is a pointer, not a value,
so it should not be referenced.

This fixes the output issue encountered during the
[2018.10 RC1 testing][RC1].

[RC1]: https://github.com/RIOT-OS/Release-Specs/issues/76#issuecomment-435924505

pkg/emb6/contrib/sock/udp/emb6_sock_udp.c

@@ -187,7 +187,7 @@ int sock_udp_recv(sock_udp_t *sock, void *data, size_t max_len,
             if (remote != NULL) {
                 remote->family = AF_INET6;
                 remote->netif = SOCK_ADDR_ANY_NETIF;
-                memcpy(&remote->addr, &sock->recv_info.src, sizeof(ipv6_addr_t));
+                memcpy(&remote->addr, sock->recv_info.src, sizeof(ipv6_addr_t));
                 remote->port = sock->recv_info.src_port;
             }
             res = (int)sock->recv_info.datalen;