netfilter: ipset: use swap macro instead of _manually_ swapping values

Make use of the swap macro and remove unnecessary variables tmp.
This makes the code easier to read and maintain.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <[e-mail]>
Signed-off-by: Jozsef Kadlecsik <[e-mail]>
Signed-off-by: Pablo Neira Ayuso <[e-mail]>

net/netfilter/ipset/ip_set_bitmap_ip.c

···
 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &last_ip);
 		if (ret)
 			return ret;
-		if (first_ip > last_ip) {
-			u32 tmp = first_ip;
-
-			first_ip = last_ip;
-			last_ip = tmp;
-		}
+		if (first_ip > last_ip)
+			swap(first_ip, last_ip);
 	} else if (tb[IPSET_ATTR_CIDR]) {
 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
 

net/netfilter/ipset/ip_set_bitmap_ipmac.c

···
 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &last_ip);
 		if (ret)
 			return ret;
-		if (first_ip > last_ip) {
-			u32 tmp = first_ip;
-
-			first_ip = last_ip;
-			last_ip = tmp;
-		}
+		if (first_ip > last_ip)
+			swap(first_ip, last_ip);
 	} else if (tb[IPSET_ATTR_CIDR]) {
 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
 

net/netfilter/ipset/ip_set_bitmap_port.c

···
 
 	first_port = ip_set_get_h16(tb[IPSET_ATTR_PORT]);
 	last_port = ip_set_get_h16(tb[IPSET_ATTR_PORT_TO]);
-	if (first_port > last_port) {
-		u16 tmp = first_port;
-
-		first_port = last_port;
-		last_port = tmp;
-	}
+	if (first_port > last_port)
+		swap(first_port, last_port);
 
 	elements = last_port - first_port + 1;
 	set->dsize = ip_set_elem_len(set, tb, 0, 0);