Free memory used in tests to enable use of valgrind

Summary: Its very usefull to be able to run valgrind on the tests and benchmarks. We were previously not freeing test memory so valgrind output was very messy.

Reviewed By: javache

Differential Revision: D3937493

fbshipit-source-id: 23c6970d7769b081575d39de583ba954fc65a397

benchmarks/CSSBenchmark.c

@@ -42,6 +42,7 @@ CSS_BENCHMARKS({
     }
 
     CSSNodeCalculateLayout(root, CSSUndefined, CSSUndefined, CSSDirectionLTR);
+    CSSNodeFreeRecursive(root);
   });
 
   CSS_BENCHMARK("Align stretch in undefined axis", {
@@ -55,6 +56,7 @@ CSS_BENCHMARKS({
     }
 
     CSSNodeCalculateLayout(root, CSSUndefined, CSSUndefined, CSSDirectionLTR);
+    CSSNodeFreeRecursive(root);
   });
 
   CSS_BENCHMARK("Nested flex", {
@@ -75,6 +77,7 @@ CSS_BENCHMARKS({
     }
 
     CSSNodeCalculateLayout(root, CSSUndefined, CSSUndefined, CSSDirectionLTR);
+    CSSNodeFreeRecursive(root);
   });
 
 });