gre: eliminate holes in ip_tunnel

The structure can be packed denser by doing minor rearrangement
of existing elements.

Signed-off-by: Stephen Hemminger <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/net/ip_tunnels.h

···
 	struct net_device	*dev;
 	struct net		*net;	/* netns for packet i/o */
 
-	int		err_count;	/* Number of arrived ICMP errors */
 	unsigned long	err_time;	/* Time when the last ICMP error
 					 * arrived */
+	int		err_count;	/* Number of arrived ICMP errors */
 
 	/* These four fields used only by GRE */
 	u32		i_seqno;	/* The last seen seqno	*/
 	u32		o_seqno;	/* The last output seqno */
 	int		tun_hlen;	/* Precalculated header length */
-	int		mlink;
 
 	struct dst_cache dst_cache;
 
 	struct ip_tunnel_parm parms;
 
+	int		mlink;
 	int		encap_hlen;	/* Encap header length (FOU,GUE) */
-	struct ip_tunnel_encap encap;
-
 	int		hlen;		/* tun_hlen + encap_hlen */
+	struct ip_tunnel_encap encap;
 
 	/* for SIT */
 #ifdef CONFIG_IPV6_SIT_6RD