ip_gre: remove redundant variables t_hlen

After commit ffc2b6ee ("ip_gre: fix IFLA_MTU ignored on NEWLINK")
variable t_hlen is assigned values that are never read,
hence they are redundant and can be removed.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/ip_gre.c

@@ -985,7 +985,6 @@ static void ipgre_tunnel_setup(struct net_device *dev)
 static void __gre_tunnel_init(struct net_device *dev)
 {
 	struct ip_tunnel *tunnel;
-	int t_hlen;
 
 	tunnel = netdev_priv(dev);
 	tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
@@ -993,8 +992,6 @@ static void __gre_tunnel_init(struct net_device *dev)
 
 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
 
-	t_hlen = tunnel->hlen + sizeof(struct iphdr);
-
 	dev->features		|= GRE_FEATURES;
 	dev->hw_features	|= GRE_FEATURES;
 
@@ -1304,13 +1301,11 @@ static const struct net_device_ops gre_tap_netdev_ops = {
 static int erspan_tunnel_init(struct net_device *dev)
 {
 	struct ip_tunnel *tunnel = netdev_priv(dev);
-	int t_hlen;
 
 	tunnel->tun_hlen = 8;
 	tunnel->parms.iph.protocol = IPPROTO_GRE;
 	tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
 		       erspan_hdr_len(tunnel->erspan_ver);
-	t_hlen = tunnel->hlen + sizeof(struct iphdr);
 
 	dev->features		|= GRE_FEATURES;
 	dev->hw_features	|= GRE_FEATURES;