Set the horizontal scanline to NULL when the vertical one fails

BUG=skia:
R=robertphillips@google.com

Author: humper@google.com

Review URL: https://codereview.chromium.org/150013004

git-svn-id: http://skia.googlecode.com/svn/trunk@13261 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed