create export should be separated from volume create (LVM Driver)

[John Griffith]

Certain iSCSI Targets can't set up the target until they have information regarding the host/initiator that the volume will be attached to, but currently in the LVM driver we deal with the target creation and export on volume create.

Move the create export out of the create method.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/69936

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/70291

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/70291
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=beecd769af02ba5915be827d28a7b46d970e41b0
Submitter: Jenkins
Branch: master

commit beecd769af02ba5915be827d28a7b46d970e41b0
Author: John Griffith <email address hidden>
Date: Fri Jan 31 03:53:37 2014 +0000

    Remove create_export from volume create

    Currently the LVM driver creates iscsi targets on
    volume creation, even though it's only used at
    attach time. This isn't necessary and in fact
    causes issues if a volume is extended because the
    target information isn't currently updated after the
    extend. In addition a number of other drivers inclduing
    the LIO iscsi driver require the target be created with
    initiator info, so the tgt that's created initially
    again isn't valid.

    This change removes the create_export call from the
    volume create process and makes it part of the
    managers intialize_connection routine which is
    more appropriate.

    This change also removes the target on detach since
    it's not used any longer and again as the volume may
    be modified or extended.

    Change-Id: I0b7dfdaf7e49a069da22f22f459861b0b49430a4
    Closes-Bug: 1248947