net: wwan: t7xx: Use needed_headroom instead of hard_header_len

hard_header_len is used by gro_list_prepare() but on Rx, there
is no header so use needed_headroom instead.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Sreehari Kancharla <sreehari.kancharla@linux.intel.com>
Reviewed-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/wwan/t7xx/t7xx_netdev.c

@@ -161,7 +161,7 @@ static void t7xx_ccmni_post_stop(struct t7xx_ccmni_ctrl *ctlb)
 
 static void t7xx_ccmni_wwan_setup(struct net_device *dev)
 {
-	dev->hard_header_len += sizeof(struct ccci_header);
+	dev->needed_headroom += sizeof(struct ccci_header);
 
 	dev->mtu = ETH_DATA_LEN;
 	dev->max_mtu = CCMNI_MTU_MAX;