Fix release build of viewer with Vulkan

Change-Id: I26c7b6030bb6be7e5005a05c593d1de40dda88db
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/299859
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
1 file changed