[skif] Cleanup comments missed in Displacement update CL

Change-Id: I594cb144f8972787b28bc0852ef5229b3664256f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/710218
Reviewed-by: Robert Phillips <robertphillips@google.com>
Auto-Submit: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
2 files changed