TCP stacks loading issue

[rrs]

Summary

The fast path.c code had the wrong module dependency (which is fixed in this revision too) but it
points out a weakness in the initialization, i.e. one must have the register function either
validate that initialization and error, or just do the initialization at that point. I choose the
later since it does no harm.

Test Plan

load the old module without changing its order and make sure we don't crash :-)