Fix MSAN issue found by fuzzer in GrStencilSettings::operator==

Change-Id: Iebe46b1ec79f7746631cf1836b896d1a39b30d08
Reviewed-on: https://skia-review.googlesource.com/10029
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
1 file changed