Fix nanobench crashes

bench/DrawLatticeBench.cpp

Index: bench/DrawLatticeBench.cpp
diff --git a/bench/DrawLatticeBench.cpp b/bench/DrawLatticeBench.cpp
index 19d549f297002ddf39fbedb203e7fed4a307e790..806815b21da844280cc0a04237a43de66ee009fb 100644
--- a/bench/DrawLatticeBench.cpp
+++ b/bench/DrawLatticeBench.cpp
@@ -22,6 +22,7 @@ public:
         fLattice.fYDivs = yDivs;
         fLattice.fYCount = yCount;
         fLattice.fFlags = nullptr;
+        fLattice.fBounds = nullptr;
 
         fName = SkStringPrintf("DrawLattice_%s", desc);
     }