Fuzzer fix for overflow in some Lut8 profiles.

Fuzzer fix for overflow in some Lut8 profiles.

Bug(?) in the tetrahedral interpolation causes output values to go out
of range a bit (1.035/1.0) in the upper range. We will just clamp for
now as a temporary fix.

BUG=668784

Change-Id: I78dd90da7174133e647b1c6c6e914dbde5de123c
Reviewed-on: https://skia-review.googlesource.com/5228
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Robert Aftias <raftias@google.com>
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2535383002
NOTREECHECKS=true
NOTRY=true
NOPRESUBMIT=true

Review-Url: https://codereview.chromium.org/2535383002