net/ipv6/udp: Fix ipv6 multicast socket filter regression

net/ipv6/udp: Fix ipv6 multicast socket filter regression

[ Upstream commit 33b4b015e1a1ca7a8fdce40af5e71642a8ea355c ]

Commit <5cf3d46192fc> ("udp: Simplify__udp*_lib_mcast_deliver")
simplified the filter for incoming IPv6 multicast but removed
the check of the local socket address and the UDP destination
address.

This patch restores the filter to prevent sockets bound to a IPv6
multicast IP to receive other UDP traffic link unicast.

Signed-off-by: Henning Rogge <hrogge@gmail.com>
Fixes: 5cf3d46192fc ("udp: Simplify__udp*_lib_mcast_deliver")
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>