Add parens to assert

TBR= robertphillips@google.com

Change-Id: Id0d7cee8a9b5f28e28e073928b29055b2efaae1c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/238858
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
1 file changed