Fix flow_extract_info() to return correct pon, onu and uni ids

This was also the root cause for auth failure after onu disable/re-enable.

Change-Id: I817a7e6c7ed38dc4f9b506fc53db58fd5e6bd30e
diff --git a/voltha/adapters/openolt/openolt_platform.py b/voltha/adapters/openolt/openolt_platform.py
index 14142d9..d592fd9 100644
--- a/voltha/adapters/openolt/openolt_platform.py
+++ b/voltha/adapters/openolt/openolt_platform.py
@@ -174,8 +174,8 @@
         if uni_port_no is None:
             raise ValueError
 
-        pon_intf = self.platform.intf_id_from_uni_port_num(uni_port_no)
-        onu_id = self.platform.onu_id_from_uni_port_num(uni_port_no)
-        uni_id = self.platform.uni_id_from_port_num(uni_port_no)
+        pon_intf = self.intf_id_from_uni_port_num(uni_port_no)
+        onu_id = self.onu_id_from_uni_port_num(uni_port_no)
+        uni_id = self.uni_id_from_port_num(uni_port_no)
 
         return pon_intf, onu_id, uni_id