[IP_VS]: Remove extra __ip_vs_conn_put() for incoming ICMP.

Remove extra __ip_vs_conn_put for incoming ICMP in direct routing
mode. Mark de Vries reports that IPVS connections are not leaked anymore.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>