qa/tasks/workunit: use suite branch/SHA1 when cloning workunits

Right now it's using the Ceph branch/SHA1 but it's using the suite
Git URL.

Signed-off-by: Jason Dillaman <dillaman@redhat.com>
(cherry picked from commit 1e3dc02)

qa/tasks/util/workunit.py

@@ -61,7 +61,8 @@ def get_refspec_after_overrides(config, overrides):
     # "tag", or "branch" is specified by a "workunit" tasks, we will update
     # it with the information in the "workunit" sub-task nested in "overrides".
     overrides = copy.deepcopy(overrides.get('workunit', {}))
-    refspecs = {'branch': Branch, 'tag': Refspec, 'sha1': Refspec}
+    refspecs = {'suite_sha1': Refspec, 'suite_branch': Branch,
+                'sha1': Refspec, 'tag': Refspec, 'branch': Branch}
     if any(map(lambda i: i in config, refspecs.iterkeys())):
         for i in refspecs.iterkeys():
             overrides.pop(i, None)