Also make swift lint strict to catch every formatting errors.

Bug: 1263872
Change-Id: Ie717c1f03ec1a0257cafceecc2055767d0be2077
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3605589Reviewed-by: Brian Ryner <bryner@google.com>
Auto-Submit: Olivier Robin <olivierrobin@chromium.org>
Commit-Queue: Olivier Robin <olivierrobin@chromium.org>
Reviewed-by: Gavin Mak <gavinmak@google.com>