Fix nanobench crashes

TBR=egdaniel@google.com
NOTRY=true
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2383223003

Review-Url: https://codereview.chromium.org/2383223003
diff --git a/bench/DrawLatticeBench.cpp b/bench/DrawLatticeBench.cpp
index 19d549f..806815b 100644
--- a/bench/DrawLatticeBench.cpp
+++ b/bench/DrawLatticeBench.cpp
@@ -22,6 +22,7 @@
         fLattice.fYDivs = yDivs;
         fLattice.fYCount = yCount;
         fLattice.fFlags = nullptr;
+        fLattice.fBounds = nullptr;
 
         fName = SkStringPrintf("DrawLattice_%s", desc);
     }