Update etc1.cpp.

I don't think our version actually has any issues since we added the else
to 0 out r2,g2, and b2. But this just updates it to look more like other
updates to etc1 outside skia.

Bug: chromium:1153993
Change-Id: I78e0b7cdd00fc9f03a2857f3d1b3502a1131a0f7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/344956
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
1 file changed