ping_table is not __read_mostly, since it contains one rwlock,
and is static to ping.c

ping_port_rover & ping_v4_lookup are static
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Acked-by: NVasiliy Kulikov <segoon@openwall.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>