Fix bookmaker dox for SkSurface::MakeRenderTarget

TBR=jvanverth@google.com
Change-Id: Iab7c69567b089941be9972367489d0c625b1898b
Reviewed-on: https://skia-review.googlesource.com/c/193378
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
1 file changed