'Get device state.
Get the device state (up/True or down/False)
@param device_mac: device mac
@param pci_slot: VF PCI slot
@return: device state (True/False) None if failed'

def get_device_state(self, device_mac, pci_slot):

    embedded_switch = self._get_emb_eswitch(device_mac, pci_slot)
    if embedded_switch:
        return embedded_switch.get_device_state(pci_slot)
    return False
