netfilter: xtables: fix warnings on 32bit platforms

On 32bit archs gcc complains due to cast from void* to u64.
Add intermediate casts to long to silence these warnings.

include/linux/netfilter/x_tables.h:376:10: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
include/linux/netfilter/x_tables.h:384:15: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
include/linux/netfilter/x_tables.h:391:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
include/linux/netfilter/x_tables.h:400:22: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

Fixes: 71ae0dff ("netfilter: xtables: use percpu rule counters")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>