Scaled endpoint tests do not pass consistently

[phudtran]

What happened:
Scaled endpoint tests only pass some of the time.
What you expected to happen:
Scaled endpoint test pass 100% of the time
How to reproduce it (as minimally and precisely as possible):
Enable the scaled endpoint test and run make e2efunctst
Anything else we need to know?:
This issue is most likely related to the port translation tcp checksum issue that @Hong-Chang discovered.