gsctool: correct a typo
gsctool: correct a typo

BUG=None
TEST=check for correct output with --help flag
BRANCH=master

Change-Id: Idf0448791e3d043313bc1291810d71d3f4846a6a
Reviewed-on: https://chromium-review.googlesource.com/1351925
Commit-Ready: Joel Kitching <c2feea8c1334a0d339e816ae4c7c9ecfa9b30a91@chromium.org>
Tested-by: Joel Kitching <c2feea8c1334a0d339e816ae4c7c9ecfa9b30a91@chromium.org>
Reviewed-by: Vadim Bendebury <5515d6d2d0829cbe0dd0dcf2094aaded06d58514@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec