Fix path issue in gate-dib-dsvm-functests

We recently added bindep support to diskimage-builder, in doing so, we
incorrectly looked in the wrong directory for the cloned project.

Change-Id: I960a466351dabae1b75c2f31183fcdb7c43fe173
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

jenkins/jobs/diskimage-builder.yaml

@@ -18,13 +18,14 @@
             openstack/dib-utils
       - shell: |
           #!/bin/bash -xe
-          cd openstack/diskimage-builder
+          cd ~/openstack/diskimage-builder
           /usr/local/jenkins/slave_scripts/install-distro-packages.sh
       - shell: |
           #!/bin/bash -eux
           #
           # We do things that might exceed the default 2GiB tmpfs, and
           # use the larger mounted space.
+          cd ~
           sudo mkdir /opt/dib_cache
           sudo chown jenkins:jenkins /opt/dib_cache
           export DIB_NO_TMPFS=1