faft: Static declaration of faft_client_attribute members

Dynamic declaration by __dict__ is not recognized by pylint. Let's move
to static declaration for easier maintenance.

BUG=chromium-os:35902
TEST=Run FAFT suite and passed.

Change-Id: Ic040f55e1b201fe32a29933b3bbcfa004e34a944
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/36994
1 file changed