netfilter: xtables: change hotdrop pointer to direct modification

Since xt_action_param is writable, let's use it. The pointer to
'bool hotdrop' always worried (8 bytes (64-bit) to write 1 byte!).
Surprisingly results in a reduction in size:

   text    data     bss filename
5457066  692730  357892 vmlinux.o-prev
5456554  692730  357892 vmlinux.o

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/net/ipv6/netfilter/ip6t_eui64.c b/net/ipv6/netfilter/ip6t_eui64.c
index f32fce3..aab0706 100644
--- a/net/ipv6/netfilter/ip6t_eui64.c
+++ b/net/ipv6/netfilter/ip6t_eui64.c
@@ -27,7 +27,7 @@
 	if (!(skb_mac_header(skb) >= skb->head &&
 	      skb_mac_header(skb) + ETH_HLEN <= skb->data) &&
 	    par->fragoff != 0) {
-		*par->hotdrop = true;
+		par->hotdrop = true;
 		return false;
 	}