Fix virDomainSnapshotObjFree memory leak.

We were freeing the virDomainSnapshotDefPtr, but not
the virDomainSnapshotObjPtr in virDomainSnapshotObjFree.
Signed-off-by: NChris Lalancette <clalance@redhat.com>

src/conf/domain_conf.c

@@ -6747,6 +6747,7 @@ static void virDomainSnapshotObjFree(virDomainSnapshotObjPtr snapshot)
     VIR_DEBUG("obj=%p", snapshot);
 
     virDomainSnapshotDefFree(snapshot->def);
+    VIR_FREE(snapshot);
 }
 
 int virDomainSnapshotObjUnref(virDomainSnapshotObjPtr snapshot)