net: dsa: remove duplicate assignment in dsa_slave_add_cls_matchall_mirred

This was caused by a poor merge conflict resolution on my side. The
"act = &cls->rule->action.entries[0];" assignment was already present in
the code prior to the patch mentioned below.

Fixes: e13c2075 ("net: dsa: refactor matchall mirred action to separate function")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dsa/slave.c

@@ -856,20 +856,18 @@ dsa_slave_add_cls_matchall_mirred(struct net_device *dev,
 	struct dsa_port *to_dp;
 	int err;
 
-	act = &cls->rule->action.entries[0];
-
 	if (!ds->ops->port_mirror_add)
 		return -EOPNOTSUPP;
 
-	if (!act->dev)
-		return -EINVAL;
-
 	if (!flow_action_basic_hw_stats_check(&cls->rule->action,
 					      cls->common.extack))
 		return -EOPNOTSUPP;
 
 	act = &cls->rule->action.entries[0];
 
+	if (!act->dev)
+		return -EINVAL;
+
 	if (!dsa_slave_dev_check(act->dev))
 		return -EOPNOTSUPP;