Return iSCSI IQN

def iscsi_iqn():
    '''
    Return iSCSI IQN
    '''
    grains = {}
    grains['iscsi_iqn'] = False
    if salt.utils.platform.is_linux():
        grains['iscsi_iqn'] = _linux_iqn()
    elif salt.utils.platform.is_windows():
        grains['iscsi_iqn'] = _windows_iqn()
    elif salt.utils.platform.is_aix():
        grains['iscsi_iqn'] = _aix_iqn()
    return grains