cfm: Make the CFM module thread safe.

Signed-off-by: Ethan Jackson <ethan@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>

vswitchd/bridge.c

@@ -1915,6 +1915,8 @@ iface_refresh_cfm_stats(struct iface *iface)
         } else {
             ovsrec_interface_set_cfm_health(cfg, NULL, 0);
         }
+
+        free(status.rmps);
     }
 }