clean up dox after enum change

Bug: skia:
Change-Id: I111c47b0134b950bcab083d1a11ab144fcf05985
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/260141
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed