change list union issue (#314)

Signed-off-by: dianew <dianew@vmware.com>

linux/device_list/vm_get_devices_with_label.yml

@@ -25,7 +25,7 @@
 
     - name: "Search all devices with label {{ device_label }}"
       set_fact:
-        vm_devices_with_label: "{{ vm_devices_with_label }} + [{{ item }}]"
+        vm_devices_with_label: "{{ vm_devices_with_label + [item] }}"
       with_items: "{{ vm_config.config.hardware.device }}"
       when: "device_label in item.deviceInfo.label"