fixed type mismatches in SkSL comparison operators

Bug: skia:
Change-Id: I8f05088c561a80549264f7a65cb8161bbe7d8f4c
Reviewed-on: https://skia-review.googlesource.com/116982
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
2 files changed