Validation for List servers by Image - expected error responses not returned

[Rohit Karajgi]

Our tempest tests run the following validation test for List Servers "by Image" API and fail
as the expected error codes are not returned.

1. test_list_servers_by_image_pass_negative_id - Return an error while listing server with negative image id

Expected Error Code - 400 BadRequest
Actual Code - 200 OK

2. test_list_servers_by_image_pass_overlimit_image - Return an error while listing server with too large image id

Expected Error Code - 413 OverLimit
Actual Code - 200 OK

3. test_list_servers_by_non_existing_image - Listing servers for a non existing image raises error

Expected Error Code - 404 NotFound
Actual Code - 200 OK

The List Servers API for listing by image should send the Expected error responses as above.

[Brian Waldon (bcwaldon)]

Similar explanation as given on this bug: https://bugs.launchpad.net/nova/+bug/1008456