net: prestera: acl: fix 'client_map' buff overflow

smatch warnings:
drivers/net/ethernet/marvell/prestera/prestera_acl.c:103
prestera_acl_chain_to_client() error: buffer overflow
'client_map' 3 <= 3

	prestera_acl_chain_to_client(u32 chain_index, ...)
        ...
	u32 client_map[] = {
		PRESTERA_HW_COUNTER_CLIENT_LOOKUP_0,
		PRESTERA_HW_COUNTER_CLIENT_LOOKUP_1,
		PRESTERA_HW_COUNTER_CLIENT_LOOKUP_2
	};
	if (chain_index > ARRAY_SIZE(client_map))
	...

Fixes: fa5d824c ("net: prestera: acl: add multi-chain support offload")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Volodymyr Mytnyk <vmytnyk@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>