Add newline at end of file.

Change-Id: I4799bbff424920b9f8d59b41dc56d1f55ef74b33
diff --git a/voltha/adapters/openolt/openolt_device.py b/voltha/adapters/openolt/openolt_device.py
index a7f3265..4736a9f 100644
--- a/voltha/adapters/openolt/openolt_device.py
+++ b/voltha/adapters/openolt/openolt_device.py
@@ -603,4 +603,4 @@
 
     def stringify_serial_number(self, serial_number):
         return ''.join([serial_number.vendor_id,
-                                     self.stringify_vendor_specific(serial_number.vendor_specific)])
\ No newline at end of file
+                                     self.stringify_vendor_specific(serial_number.vendor_specific)])