ipv4: icmp: do not process ICMP_EXT_ECHOREPLY for broadcast/multicast addresses

There is no point processing ICMP_EXT_ECHOREPLY for routes
which would drop ICMP_ECHOREPLY (RFC 1122 3.2.2.6, 3.2.2.8)

This seems an oversight of the initial implementation.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250226183437.1457318-2-edumazet@google.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>