Small cleanups to drawVertices

Change-Id: I16301e6fb7193ba67b9fea292f931fda480c8ac3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/420956
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2 files changed