datapath: lisp: Fix uninitialized field in tunnel_cfg.

The tunnel_cfg had the gro_receive and gro_complete fields uninitialized
in function lisp_open(). This caused an uninitialized memory read.

Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>
Reviewed-by: Greg Rose <gvrose8192@gmail.com>

datapath/linux/compat/lisp.c

@@ -457,6 +457,7 @@ static int lisp_open(struct net_device *dev)
 
 	rcu_assign_pointer(lisp->sock, sock);
 	/* Mark socket as an encapsulation socket */
+	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
 	tunnel_cfg.sk_user_data = dev;
 	tunnel_cfg.encap_type = 1;
 	tunnel_cfg.encap_rcv = lisp_rcv;