some pathops fuzz fixes

R=kjlubick@google.com
Bug: skia:
Change-Id: I0b2089f728f91ef5af780d0e9f91d266c252c054
Reviewed-on: https://skia-review.googlesource.com/c/169341
Auto-Submit: Cary Clark <caryclark@skia.org>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
5 files changed