conn_init: fix self assigned variable

Summary:
This was done because pEndOfCfg is unused,
and self assigning is an error (with Werror)
in Clang. Let's use C casting as void instead.

Test Plan: verify

Reviewers: Roach, ConnorBaker, synergy

Reviewed By: synergy

Differential Revision: http://review.codefirex.com/D581

Change-Id: Ifea8a44579ef842ceed4837791a5a5142d0e3bc4