SkLiteDL: tiny perf tweak

src/core/SkLiteDL.cpp

Index: src/core/SkLiteDL.cpp
diff --git a/src/core/SkLiteDL.cpp b/src/core/SkLiteDL.cpp
index 329edb046b30b819cedf562e086dd51747cc6016..8dad6f40e482c04ef4200a6f35a6c7d5bb6e714b 100644
--- a/src/core/SkLiteDL.cpp
+++ b/src/core/SkLiteDL.cpp
@@ -478,7 +478,8 @@ static void* push(SkTDArray<uint8_t>* bytes, size_t pod, Args&&... args) {
 
 template <typename Fn>
 static void map(SkTDArray<uint8_t>* bytes, Fn&& fn) {
-    for (uint8_t* ptr = bytes->begin(); ptr < bytes->end(); ) {
+    auto end = bytes->end();
+    for (uint8_t* ptr = bytes->begin(); ptr < end; ) {
         auto op = (Op*)ptr;
         fn(op);
         ptr += op->skip;