More review fixes

fixtures/benchmarks/README.md

@@ -8,10 +8,10 @@ the foreign language:
    the benchmarks for.
  - `benchmarks.rs` executes a script for each foreign language that we want to benchmark.
  - Those scripts call the `run_benchmarks()` function from `lib.rs`
- - `run_benchmarks()` parses the CLI arguments again, this time to how to setup
+ - `run_benchmarks()` parses the CLI arguments again, this time to determine how to setup
    the `Criterion` object.
  - Testing callback interfaces is relatively straightforward, we simply invoke
    the callback method.
  - Testing regular functions requires some extra care, since these are called
    by the foreign bindings.  To test those, `benchmarks.rs` invokes a callback
-   interface method that call the rust function and reports the time taken.
+   interface method that calls the Rust function and reports the time taken.