[wasm][fuzzer] Fix SubVector call

This is a follow-up to https://crrev.com/c/2249928. The arguments for
{SubVector} are {from, to}, not {from, size}.

R=jkummerow@chromium.org

Bug: chromium:1097442
Change-Id: I3c5571ff7f0c6b8e235ecf4164591630dbd05739
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2255465Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68451}

test/fuzzer/wasm-compile.cc

@@ -1554,7 +1554,7 @@ void WasmGenerator::Generate(Vector<const ValueType> types, DataRange* data) {
   size_t split_index = data->get<uint8_t>() % (types.size() - 1) + 1;
   Vector<const ValueType> lower_half = types.SubVector(0, split_index);
   Vector<const ValueType> upper_half =
-      types.SubVector(split_index, types.size() - split_index);
+      types.SubVector(split_index, types.size());
   DataRange first_range = data->split();
   Generate(lower_half, &first_range);
   Generate(upper_half, data);