lwtunnel: change to use nla_put_u8 for LWTUNNEL_IP_OPT_ERSPAN_VER

LWTUNNEL_IP_OPT_ERSPAN_VER is u8 type, and nla_put_u8 should have
been used instead of nla_put_u32(). This is a copy-paste error.

Fixes: b0a21810 ("lwtunnel: add options setting and dumping for erspan")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/ip_tunnel_core.c

@@ -526,7 +526,7 @@ static int ip_tun_fill_encap_opts_erspan(struct sk_buff *skb,
 		return -ENOMEM;
 
 	md = ip_tunnel_info_opts(tun_info);
-	if (nla_put_u32(skb, LWTUNNEL_IP_OPT_ERSPAN_VER, md->version))
+	if (nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_VER, md->version))
 		goto err;
 
 	if (md->version == 1 &&