net: dsa: sja1105: unconditionally free old gating config

Currently sja1105_compose_gating_subschedule is not prepared to be
called for the case where we want to recompute the global tc-gate
configuration after we've deleted those actions on a port.

After deleting the tc-gate actions on the last port, max_cycle_time
would become zero, and that would incorrectly prevent
sja1105_free_gating_config from getting called.

So move the freeing function above the check for the need to apply a new
configuration.

Fixes: 834f8933 ("net: dsa: sja1105: implement tc-gate using time-triggered virtual links")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/sja1105/sja1105_vl.c

@@ -98,6 +98,8 @@ static int sja1105_compose_gating_subschedule(struct sja1105_private *priv,
 	s64 its_base_time = 0;
 	int i, rc = 0;
 
+	sja1105_free_gating_config(gating_cfg);
+
 	list_for_each_entry(rule, &priv->flow_block.rules, list) {
 		if (rule->type != SJA1105_RULE_VL)
 			continue;
@@ -116,8 +118,6 @@ static int sja1105_compose_gating_subschedule(struct sja1105_private *priv,
 	dev_dbg(priv->ds->dev, "max_cycle_time %lld its_base_time %lld\n",
 		max_cycle_time, its_base_time);
 
-	sja1105_free_gating_config(gating_cfg);
-
 	gating_cfg->base_time = its_base_time;
 	gating_cfg->cycle_time = max_cycle_time;
 	gating_cfg->num_entries = 0;