ofp-actions: Rename ofpact_update_len() to ofpact_finish().

It does more than just update the length now, so this is a more accurate
name.

Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Russell Bryant <russell@ovn.org>

lib/learn.c

@@ -379,7 +379,7 @@ learn_parse__(char *orig, char *arg, struct ofpbuf *ofpacts)
             }
         }
     }
-    ofpact_update_len(ofpacts, &learn->ofpact);
+    ofpact_finish(ofpacts, &learn->ofpact);
 
     return NULL;
 }