openvswitch: Use proper buffer size in nla_memcpy

For the input parameter count, it's better to use the size
of destination buffer size, as nla_memcpy would take into
account the length of the source netlink attribute when
a data is copied from an attribute.

Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/openvswitch/conntrack.c

@@ -968,7 +968,8 @@ static int parse_nat(const struct nlattr *attr,
 			break;
 
 		case OVS_NAT_ATTR_IP_MIN:
-			nla_memcpy(&info->range.min_addr, a, nla_len(a));
+			nla_memcpy(&info->range.min_addr, a,
+				   sizeof(info->range.min_addr));
 			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
 			break;