Fix asan build. Duh, don't return a stack address...

bench/MathBench.cpp

 #include "SkBenchmark.h"
 #include "SkColorPriv.h"
 #include "SkMatrix.h"
 #include "SkRandom.h"
 #include "SkString.h"
 #include "SkPaint.h"
 
 static float sk_fsel(float pred, float result_ge, float result_lt) {
     return pred >= 0 ? result_ge : result_lt;
 }
@@ skipping 496 matching lines @@
     }
 
 private:
     typedef SkBenchmark INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 template <typename T>
 class DivModBench : public SkBenchmark {
-    const char* fName;
+    SkString fName;
 public:
-    explicit DivModBench(const char* name) : fName(name) {
+    explicit DivModBench(const char* name) {
+        fName.printf("divmod_%s", name);
         fIsRendering = false;
     }
 
 protected:
     virtual const char* onGetName() {
-        return SkStringPrintf("divmod_%s", fName).c_str();
+        return fName.c_str();
     }
 
     virtual void onDraw(SkCanvas*) {
         volatile T a = 0, b = 0;
         T div = 0, mod = 0;
         for (int i = 0; i < this->getLoops(); i++) {
             if ((T)i == 0) continue;  // Small T will wrap around.
             SkTDivMod((T)(i+1), (T)i, &div, &mod);
             a ^= div;
             b ^= mod;
@@ skipping 28 matching lines @@
 
 DEF_BENCH( return new FloorBench(false); )
 DEF_BENCH( return new FloorBench(true); )
 
 DEF_BENCH( return new CLZBench(false); )
 DEF_BENCH( return new CLZBench(true); )
 
 DEF_BENCH( return new NormalizeBench(); )
 
 DEF_BENCH( return new FixedMathBench(); )