Simplify ddlbench a bit

Change-Id: I5ed062172645ed8e7ae238e629dcc1af5b0357cf
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/374118
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Adlai Holler <adlai@google.com>
1 file changed