parse: remove uses of from module import *

Since there is now both an action class named "vendor" and a message class
named "vendor" they clash when imported into the same namespace.
diff --git a/tests/flow_query.py b/tests/flow_query.py
index 476cd75..403d138 100644
--- a/tests/flow_query.py
+++ b/tests/flow_query.py
@@ -338,7 +338,7 @@
 
     def __init__(self):
         self.priority        = 0
-        self.match           = parse.ofp_match()
+        self.match           = ofp.ofp_match()
         self.match.wildcards = ofp.OFPFW_ALL
         self.idle_timeout    = 0
         self.hard_timeout    = 0