[iptables PATCH] list: fix prefetch dummy

[Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>]

linux_list.h:381:59: warning: right-hand operand of comma expression has no effect [-Wunused-value]
  for (pos = list_entry((head)->next, typeof(*pos), member), \
                                                           ^
libiptc.c:552:2: note: in expansion of macro 'list_for_each_entry'
  list_for_each_entry(c, &h->chains, list) {
  ^

[ Patch copied from one similar of Patrick McHardy on libnftnl ]

Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
---
 libiptc/linux_list.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libiptc/linux_list.h b/libiptc/linux_list.h
index abdcf88..559e33c 100644
--- a/libiptc/linux_list.h
+++ b/libiptc/linux_list.h
@@ -27,7 +27,7 @@
 	1; \
 })
 
-#define prefetch(x)		1
+#define prefetch(x)		((void)0)
 
 /* empty define to make this work in userspace -HW */
 #define smp_wmb()