Mark other makeVertexWriter checks as unlikely/likely

We usually don't run out of memory, so this can perhaps improve
branching behavior.

Change-Id: Ia11cbd73fa4d4c6aa9caa5cf4265dea931923546
Bug: b/467843949
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1123217
Reviewed-by: Robert Phillips <robertphillips@google.com>
7 files changed