Fix bookmaker compile warning

Bug: skia:
Change-Id: Iee8cf7f1d51f965e19bfc69190f975184bd7ff7a
Reviewed-on: https://skia-review.googlesource.com/66148
Commit-Queue: Cary Clark <caryclark@google.com>
Reviewed-by: Cary Clark <caryclark@google.com>
1 file changed