mlxsw: spectrum: Update sch_prio stats to include sch_red related drops

sch_prio as root qdisc should count all the drops its children have. Since
it is possible for it to have sch_red children, it needs to count RED early
drops.
Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Reviewed-by: Yuval Mintz <yuvalm@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c

@@ -584,6 +584,7 @@ mlxsw_sp_qdisc_get_prio_stats(struct mlxsw_sp_port *mlxsw_sp_port,
 
 	for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++) {
 		drops += xstats->tail_drop[i];
+		drops += xstats->wred_drop[i];
 		backlog += xstats->backlog[i];
 	}
 	drops = drops - stats_base->drops;
@@ -619,8 +620,10 @@ mlxsw_sp_setup_tc_qdisc_prio_clean_stats(struct mlxsw_sp_port *mlxsw_sp_port,
 	stats_base->tx_bytes = stats->tx_bytes;
 
 	stats_base->drops = 0;
-	for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++)
+	for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++) {
 		stats_base->drops += xstats->tail_drop[i];
+		stats_base->drops += xstats->wred_drop[i];
+	}
 
 	mlxsw_sp_qdisc->stats_base.backlog = 0;
 }