Comment 4 for bug 1765000

Reviewed: https://review.openstack.org/564724
Committed: https://git.openstack.org/cgit/openstack/os-brick/commit/?id=8fab1a01cb03155e05f8a9211b152a4938474575
Submitter: Zuul
Branch: stable/queens

commit 8fab1a01cb03155e05f8a9211b152a4938474575
Author: Gorka Eguileor <email address hidden>
Date: Wed Apr 18 12:34:37 2018 +0200

    Fix FC: Only scan connected HBAs

    Current OS-Brick FC code always scans all present HBAs, which could
    unintentionally add unwanted devices, for example in the following
    environment:

        +-------+ +------+ +-----------------+
        | host5 +-----+ +---+ Port.A VNX |
        | | | FCSW +---+ Port.B |
        | host6 +-----+ | +-----------------+
        | | +------+
        | | +------+
        | host7 +-----+ | +-----------------+
        | | | FCSW +---+ Port.C XtremIO |
        | host8 +-----+ +---+ Port.D |
        +-------+ +------+ +-----------------+

    This patch limits what HBAs get scanned:

    - If we have an initiator map, we only scan on the HBAs that are there
    - If we are in the single WWNN for all ports case we only scan HBAs that
      are connected
    - If we can't do any better we scan all HBAs with wildcards

    Closes-Bug: #1765000
    Change-Id: I3ba8f9683211d550727a97fc455175f2b0482886
    (cherry picked from commit db40d980440ef6ceed5dcd711d6818971498007c)