Fix off-by-one in four_byte_interp benches.

bench/ColorPrivBench.cpp

Index: bench/ColorPrivBench.cpp
diff --git a/bench/ColorPrivBench.cpp b/bench/ColorPrivBench.cpp
index 3143ef45256f321feeb5442cd03f4630840392d9..1e152e6d626d5d0c2078032a9b4ae4680f3e7b35 100644
--- a/bench/ColorPrivBench.cpp
+++ b/bench/ColorPrivBench.cpp
@@ -28,7 +28,7 @@ public:
         const SkPMColor src = 0xAB998877, dst = 0x66334455;
         volatile SkPMColor junk = 0;
         for (int i = 0; i < 10*this->getLoops(); ++i) {
-            for (size_t j = 0; j <= SK_ARRAY_COUNT(fScales); j++) {
+            for (size_t j = 0; j <= 256; j++) {
                 const unsigned scale = fScales[j];
                 if (kFast && kScale) {
                     junk ^= SkFastFourByteInterp(src, dst, scale);