[NETFILTER]: x_tables: remove some unnecessary casts

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/xt_mark.c b/net/netfilter/xt_mark.c
index 8b385a3..876bc57 100644
--- a/net/netfilter/xt_mark.c
+++ b/net/netfilter/xt_mark.c
@@ -42,7 +42,7 @@
            unsigned int matchsize,
            unsigned int hook_mask)
 {
-	struct xt_mark_info *minfo = (struct xt_mark_info *) matchinfo;
+	const struct xt_mark_info *minfo = matchinfo;
 
 	if (minfo->mark > 0xffffffff || minfo->mask > 0xffffffff) {
 		printk(KERN_WARNING "mark: only supports 32bit mark\n");