GrTessellator: fix compile when LOGGING_ENABLED.

BUG=skia:

Change-Id: I1f0df58ffe79e439f92a8c1cd3c39812c32d039f
Reviewed-on: https://skia-review.googlesource.com/6743
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Stephan White <senorblanco@chromium.org>
1 file changed