Free allocated memory in torque driver

This is a minor memory leak if the cluster_label struct member is
set in the driver.

Also sort the free statements to match the order in the defining struct.

src/clib/lib/job_queue/torque_driver.cpp

@@ -819,14 +819,16 @@ void torque_driver_kill_job(void *__driver, void *__job) {
 void torque_driver_free(torque_driver_type *driver) {
     torque_driver_set_debug_output(driver, NULL);
     free(driver->queue_name);
-    free(driver->qdel_cmd);
+    free(driver->qsub_cmd);
     free(driver->qstat_cmd);
     free(driver->qstat_opts);
-    free(driver->qsub_cmd);
+    free(driver->qdel_cmd);
     free(driver->num_cpus_per_node_char);
     free(driver->num_nodes_char);
     if (driver->job_prefix)
         free(driver->job_prefix);
+    if (driver->cluster_label)
+        free(driver->cluster_label)
 
     free(driver);
 }