servod: send sighup to user pty

This allows ec3po to detect pts open and close, to avoid writing
to a closed ptm. This works around an issue where the pty buffer
would fill and cause ec3po to hang.

BUG=b:76111225
TEST=dut-control ec_board:fizz x 400

Change-Id: Ic9897153697453be9a9f66ee10947b6d6a64be2d
Signed-off-by: Nick Sanders <nsanders@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1014793
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>
1 file changed