Don't use slashes for long lines - use parentheses instead

[Roman Vasilets]

According to the OpenStack Style Guidelines - http://docs.openstack.org/developer/hacking/#general - it is prefered to wrap
long lines in parentheses and not a backslash for line continuation. As
we are following those guidelines in our project - we should replace backslash with parentheses for line continuation.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/136012

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/136012
Committed: https://git.openstack.org/cgit/openstack/glance/commit/?id=2008c55f2621d3608c38d9e270f84173c15e270c
Submitter: Jenkins
Branch: master

commit 2008c55f2621d3608c38d9e270f84173c15e270c
Author: Roman Vasilets <email address hidden>
Date: Thu Nov 20 16:45:09 2014 +0200

    Don't use slashes for long lines - use parentheses instead

    According to the OpenStack Style Guidelines [1] it is prefered to wrap
    long lines in parentheses and not a backslash for line continuation. As
    we are following those guidelines in our project - this patch replaces
    backslash with parentheses for line continuation.

    _[1] http://docs.openstack.org/developer/hacking/#general

    Co-Authored-By: Roman Vasilets <email address hidden>
    Co-Authored-By: Kamil Rykowski <email address hidden>

    Change-Id: I1743a539703c964277b0e8da203ee46bc8014fb5
    Closes-bug: 1394605