Trying to set a property on a device that does not exist is not something
necessarily wrong. Don't print error/warning messages.

    <trace> [1467707267.2887] device[0x55a74adbdaf0] (enp0s25): set-hw-addr: setting MAC address to 'AA:BB:CC:DD:EE:FF' (reset, unmanage)...
    <debug> [1467707267.2887] platform: link: setting '(null)' (2) hardware address
    <debug> [1467707267.2887] platform-linux: link: change 2: address: 68:F7:28:61:68:F7 (6 bytes)
    <debug> [1467707267.2887] platform-linux: do-request-link: 2
    <debug> [1467707267.2888] platform-linux: netlink: recvmsg: error message from kernel: No such device (19) for request 226
    <debug> [1467707267.2888] platform-linux: netlink: recvmsg: error message from kernel: No such device (19) for request 227
    <error> [1467707267.2888] platform-linux: do-change-link[2]: failure changing link: failure 19 (No such device)
    <warn>  [1467707267.2888] device (enp0s25): set-hw-addr: failed to reset MAC address to 68:F7:28:61:68:F7 (unmanage)