Add missing nextafter() clamping to SkLinearBitmapPipeline tile procs

Fixes the asserts trigered in
https://skia-review.googlesource.com/c/7615

Change-Id: I7e1802bc699becf85396445fe0df4cb110ab69c4
Reviewed-on: https://skia-review.googlesource.com/7720
Commit-Queue: Florin Malita <fmalita@chromium.org>
Reviewed-by: Herb Derby <herb@google.com>
1 file changed