[graphite] Fix vello build typo in RendererProvider

Change-Id: Ie202f1a11da7d113a45682033bbacc4ea3804ee2
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1123516
Auto-Submit: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Kaylee Lubick <kjlubick@google.com>
Reviewed-by: Kaylee Lubick <kjlubick@google.com>
1 file changed