bridge: Fix MLD queries' ethernet source address

Map the IPv6 header's destination multicast address to an ethernet
source address instead of the MLD queries multicast address.

For instance for a general MLD query (multicast address in the MLD query
set to ::), this would wrongly be mapped to 33:33:00:00:00:00, although
an MLD queries destination MAC should always be 33:33:00:00:00:01 which
matches the IPv6 header's multicast destination ff02::1.
Signed-off-by: NLinus Lüssing <linus.luessing@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/bridge/br_multicast.c

@@ -434,7 +434,6 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
 	eth = eth_hdr(skb);
 
 	memcpy(eth->h_source, br->dev->dev_addr, 6);
-	ipv6_eth_mc_map(group, eth->h_dest);
 	eth->h_proto = htons(ETH_P_IPV6);
 	skb_put(skb, sizeof(*eth));
 
@@ -448,6 +447,7 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
 	ip6h->hop_limit = 1;
 	ipv6_addr_set(&ip6h->saddr, 0, 0, 0, 0);
 	ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
+	ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
 
 	hopopt = (u8 *)(ip6h + 1);
 	hopopt[0] = IPPROTO_ICMPV6;		/* next hdr */