fonts: Fix nullptr de-reference during fallback path search.

R=herb@google.com

Bug: 892643
Change-Id: Ia059e784794ff07f654a538186e619fb4f303ec9
Reviewed-on: https://skia-review.googlesource.com/c/160834
Commit-Queue: Khusal Sagar <khushalsagar@chromium.org>
Commit-Queue: Herb Derby <herb@google.com>
Auto-Submit: Khusal Sagar <khushalsagar@chromium.org>
Reviewed-by: Herb Derby <herb@google.com>
1 file changed