folly/test/FBVectorTestBenchmarks.cpp.h: remove unused argument

Summary: Remove unused argument `iters`.

Reviewed By: meyering

Differential Revision: D2872551

fb-gh-sync-id: 0989e5b256d4d80dd3ad02401e3fc65d0f749ba6

folly/test/FBVectorTestBenchmarks.cpp.h

@@ -302,7 +302,7 @@ TESTFUN(clause_23_3_6_4_clear) {
   EXPECT_EQ(v.capacity(), c);
 }
 
-BENCHMARK(BENCHFUN(zzInitRNG), iters) {
+BENCHMARK(BENCHFUN(zzInitRNG)) {
   //LOG(INFO) << "\nTesting with type " << typeid(VECTOR).name() << "\n";
   srand(seed);
 }