Fix degenerate case handling in fill_in_2D_gaussian_kernel

Bug: 849016
Change-Id: Icc46451acd83140cb86593195947efea7f83828d
Reviewed-on: https://skia-review.googlesource.com/135142
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Herb Derby <herb@google.com>
1 file changed