net: mpls: Convert number of nexthops to u8

Number of nexthops and number of alive nexthops are tracked using an
unsigned int. A route should never have more than 255 nexthops so
convert both to u8. Update all references and intermediate variables
to consistently use u8 as well.

Shrinks the size of mpls_route from 32 bytes to 24 bytes with a 2-byte
hole before the nexthops.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/mpls/internal.h b/net/mpls/internal.h
index 91419fe..2ac9743 100644
--- a/net/mpls/internal.h
+++ b/net/mpls/internal.h
@@ -127,12 +127,13 @@ struct mpls_route { /* next hop label forwarding entry */
 	u8			rt_payload_type;
 	u8			rt_max_alen;
 	u8			rt_ttl_propagate;
-	unsigned int		rt_nhn;
+	u8			rt_nhn;
 
 	/* rt_nhn_alive is accessed under RCU in the packet path; it
 	 * is modified handling netdev events with rtnl lock held
 	 */
-	unsigned int		rt_nhn_alive;
+	u8			rt_nhn_alive;
+	u16			rt_reserved1;
 	struct mpls_nh		rt_nh[0];
 };