Fix control interface for hostapd instances

Fix deauth_client to glean the control interface out of the
config dictionary for the instance instead of expecting it to
be at the top-level instance.  While here, generate a
per-interface control interface file

BUG=None
TEST=New test which calls deauth_client

Change-Id: I5e5e5258330d8ac373eb1a6d615474a77441f9b7
Reviewed-on: https://chromium-review.googlesource.com/183544
Reviewed-by: Christopher Wiley <wiley@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
Commit-Queue: Paul Stewart <pstew@chromium.org>
1 file changed