Fix Bug 2009 use existing volumes as instantiation parameters

Change-Id: I8bed540aea41c23eef5ff4bf25f7ea03d77ba064
Signed-off-by: aticig <gulsum.atici@canonical.com>
diff --git a/osm_nbi/instance_topics.py b/osm_nbi/instance_topics.py
index d371216..62df4f8 100644
--- a/osm_nbi/instance_topics.py
+++ b/osm_nbi/instance_topics.py
@@ -1488,7 +1488,7 @@
                 if in_vdu["id"] == vdu["id"]:
                     for volume in get_iterable(in_vdu.get("volume")):
                         for volumed in get_iterable(vdu.get("virtual-storage-desc")):
-                            if volumed["id"] == volume["name"]:
+                            if volumed == volume["name"]:
                                 break
                         else:
                             raise EngineException(
@@ -1508,7 +1508,7 @@
                         ):
                             vdu_if_names.add(iface.get("name"))
 
-                    for in_iface in get_iterable(in_vdu["interface"]):
+                    for in_iface in get_iterable(in_vdu.get("interface")):
                         if in_iface["name"] in vdu_if_names:
                             break
                         else: