Fixed another division by zero error in skslc
Fixed another division by zero error in skslc

You'd think by now it would have occurred to me that mod is also a kind
of division.

BUG=skia:6087

Change-Id: I5128d09db94d06f10762ad5c23df32551c5e5855
Reviewed-on: https://skia-review.googlesource.com/6607
Reviewed-by: Greg Daniel <39df0a804564ccb6cf75f18db79653821f37c1c5@google.com>
Commit-Queue: Ethan Nicholas <d2cfb8c2f603266f4dc3a6f09acbcc0089603b37@google.com>

Hikari-no-Tenshi/android_external_skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,HalCanary/skia-hc,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,google/skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,HalCanary/skia-hc,google/skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,google/skia,aosp-mirror/platform_external_skia,rubenvb/skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,rubenvb/skia,HalCanary/skia-hc,google/skia,HalCanary/skia-hc,google/skia,HalCanary/skia-hc,HalCanary/skia-hc,google/skia,Hikari-no-Tenshi/android_external_skia,google/skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,rubenvb/skia,rubenvb/skia,google/skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,rubenvb/skia