Change SAD-test offset.
Change SAD-test offset.

Using 3 instead of 4 avoids having symmetric negation of the offset, like
-4 and +4. It also makes the expected result easier to calculate by hand.

ultravideo/kvazaar,lu-zero/kvazaar,ultravideo/kvazaar,ultravideo/kvazaar,lu-zero/kvazaar,ultravideo/kvazaar,lu-zero/kvazaar,ultravideo/kvazaar,lu-zero/kvazaar