SolidFire api call response checks are inconsistent and not needed

[John Griffith]

Over time we've moved the API response verification into the issue_api_call method. In that method we check for a valid response and raise if it's not valid. The problem is we still have a mix of the old code where each caller verifies the response themselves. This is pointless because the _issue_api_request will raise if the response isn't valid and the check will never actually "do" anything.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/219756

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/219756
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=3b90fc7e9728c7eda45cf50259e6c5d249b5d4c9
Submitter: Jenkins
Branch: master

commit 3b90fc7e9728c7eda45cf50259e6c5d249b5d4c9
Author: John Griffith <email address hidden>
Date: Wed Sep 2 15:56:15 2015 +0000

    Remove useless response checks in SolidFire driver

    The main issue_api_request method in the SolidFire driver
    has had a mechanism to check validity of response data for
    some time now. It checks the response and if there isn't
    a valid result in the response it raises.

    The problem is that we still have some cruft from the old
    code that does local checking/verfication. These checks
    won't ever actually be called because of the exception, and
    they create some confusion.

    This patch just removes those useless checks and cleans up
    the api_request calls a bit.

    Change-Id: Ifbcda0f943bb0b9dc47aff25bbb9245ce361fc48
    Closes-Bug: #1491485