ip6tables: fix printing of ipv6 network masks

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/xtables.c b/xtables.c
index 8241687..a97bdaa 100644
--- a/xtables.c
+++ b/xtables.c
@@ -1011,10 +1011,10 @@
 	unsigned int bits = 0;
 	uint32_t a, b, c, d;
 
-	a = k->s6_addr32[0];
-	b = k->s6_addr32[1];
-	c = k->s6_addr32[2];
-	d = k->s6_addr32[3];
+	a = ntohl(k->s6_addr32[0]);
+	b = ntohl(k->s6_addr32[1]);
+	c = ntohl(k->s6_addr32[2]);
+	d = ntohl(k->s6_addr32[3]);
 	while (a & 0x80000000U) {
 		++bits;
 		a <<= 1;