platform/chrome: cros_ec_lightbar: Fix response size initialization

platform/chrome: cros_ec_lightbar: Fix response size initialization

Commit 1e7913ff5f9f ("platform/chrome: cros_ec_lightbar: Reduce
ligthbar get version command") meant to set smaller values for both
request and response sizes.

However, it incorrectly assigned the response size to the `result` field
instead of `insize`.  Fix it.

Reported-by: Gwendal Grignou <gwendal@google.com>
Closes: https://lore.kernel.org/chrome-platform/CAMHSBOVrrYaB=1nEqZk09VkczCrj=6B-P8Fe29TpPdSDgT2CCQ@mail.gmail.com
Fixes: 1e7913ff5f9f ("platform/chrome: cros_ec_lightbar: Reduce ligthbar get version command")
Link: https://lore.kernel.org/r/20260130040335.361997-1-tzungbi@kernel.org
Reviewed-by: Gwendal Grignou <gwendal@google.com>
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>