Replace usage of 'user' by 'user_id'
Replace usage of 'user' by 'user_id'

DeprecationWarning: Using the 'user' argument is deprecated
in version '2.18' and will be removed in version '3.0'

Change-Id: I96061cf624c84145c4ec7031414aecb58c2ced79

huntxu/neutron,openstack/neutron,mahak/neutron,mahak/neutron,mahak/neutron,openstack/neutron,noironetworks/neutron,huntxu/neutron,openstack/neutron,noironetworks/neutron